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Author |
Vanmeert, F.; de Nolf, W.; De Meyer, S.; Dik, J.; Janssens, K. |
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Title |
Macroscopic X-ray powder diffraction scanning, a new method for highly selective chemical imaging of works of art : instrument optimization |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
90 |
Issue |
11 |
Pages |
6436-6444 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
In the past decade macroscopic X-ray fluorescence imaging (MA-XRF) has become established as a method for the noninvasive investigation of flat painted surfaces, yielding large scale elemental maps. MA-XRF is limited by a lack of specificity, only allowing for indirect pigment identification based on the simultaneous presence of chemical elements. The high specificity of X-ray powder diffraction (XRPD) mapping is already being exploited at synchrotron facilities for investigations at the (sub)microscopic scale, but the technique has not yet been employed using lab sources. In this paper we present the development of a novel MA-XRPD/XRF instrument based on a laboratory X-ray source. Several combinations of X-ray sources and area detectors are evaluated in terms of their spatial and angular resolution and their sensitivity. The highly specific imaging capability of the combined MA-XRPD/XRF instrument is demonstrated on a 15th/16th century illuminated manuscript directly revealing the distribution of a large number of inorganic pigments, including the uncommon yellow pigment massicot (o-PbO). The case study illustrates the wealth of new mapping information that can be obtained in a noninvasive manner using the laboratory MA-XRPD/XRF instrument. |
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Wos |
000434893200019 |
Publication Date |
2018-04-06 |
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ISSN |
0003-2700; 5206-882x |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
11 |
Open Access |
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Notes |
; The authors thank the persons involved at Incoatec GmbH, imXPAD SAS and Dectris Ltd. for loaning us some of their products over the past years. We acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” Project and GOA Project Solarpaint (University of Antwerp Research Council). Photo Copyright Geert Van der Snickt, 2008 for the photograph of the illuminated manuscript in the TOC graphic. ; |
Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:151993 |
Serial |
5701 |
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Author |
De Jong, M.; Florea, A.; de Vries, A.-M.; van Nuijs, A.L.N.; Covaci, A.; Van Durme, F.; Martins, J.C.; Samyn, N.; De Wael, K. |
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Title |
Levamisole : a common adulterant in cocaine street samples hindering electrochemical detection of cocaine |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
90 |
Issue |
8 |
Pages |
5290-5297 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre |
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Abstract |
The present work investigates the electrochemical determination of cocaine in the presence of levamisole, one of the most common adulterants found in cocaine street samples. Levamisole misleads cocaine color tests, giving a blue color (positive test) even in the absence of cocaine. Moreover, the electrochemical detection of cocaine is also affected by the presence of levamisole, with a suppression of the oxidation signal of cocaine. When levamisole is present in the sample in ratios higher than 1:1, the cocaine signal is no longer detected, thus leading to false negative results. Mass spectrometry and nuclear magnetic resonance were used to investigate if the signal suppression is due to the formation of a complex between cocaine and levamisole in bulk solution. Strategies to eliminate this suppressing effect are further suggested in this manuscript. In a first approach, the increase of the pH of the sample solution from pH 7 to pH 12 allowed the voltammetric determination of cocaine in the presence of levamisole in a concentration range from 10 to 5000 μM at nonmodified graphite disposable electrodes with a detection limit of 5 μM. In a second approach, the graphite electrode was cathodically pretreated, resulting in the presence of oxidation peaks of both cocaine and levamisole, with a detection limit for cocaine of 3 μM over the linear range of concentrations from 10 to 2500 μM. Both these strategies have been successfully applied for the simultaneous detection of cocaine and levamisole in three street samples on unmodified graphite disposable electrodes. |
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Wos |
000430512200049 |
Publication Date |
2018-02-23 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
8 |
Open Access |
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Notes |
; This project has received funding from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. This work was also supported by BR/314/PI/ APTADRU Project and IOF-SBO (UAntwerp). Alexander van Nuijs acknowledges the Research Foundation-Flanders (FWO) for his postdoctoral fellowship. ; |
Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:149528 |
Serial |
5693 |
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Author |
Cagno, S.; Brede, D.A.; Nuyts, G.; Vanmeert, F.; Pacureanu, A.; Tucoulou, R.; Cloetens, P.; Falkenberg, G.; Janssens, K.; Salbu, B.; Lind, O.C. |
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Title |
Combined computed nanotomography and nanoscopic x-ray fluorescence imaging of cobalt nanoparticles in caenorhabditis elegans |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
89 |
Issue |
21 |
Pages |
11435-11442 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Synchrotron radiation phase-contrast computed nanotomography (nano-CT) and two-and three-dimensional (2D and 3D) nanoscopic X-ray fluorescence (nano-XRF) were used to investigate the internal distribution of engineered-cobalt nanoparticles (Co NPs) in exposed individuals of the nematode Caenorhabditis elegans. Whole-nematodes and selected tissues and organs were 3D-rendered: anatomical 3D renderings with 50 nm voxel size enabled the visualization of spherical nanoparticle aggregates. with size tip to 200 nm within intact C. elegans. A 20 X 37 nm(2) high-brilliance beam was employed to obtain XRF elemental distribution maps of entire nematodes or anatomical details such as embryos, which could be compared with the CT data, These maps showed Co NPs to be predominantly present within the intestine and the epithelium, and they were not colocalized with Zn granules found in the lysosonie-containing vesicles or Fe agglomerates in the intestine. Iterated XRF scanning of a specimen at 0 degrees and 90 degrees angles suggested that NP aggregates were translocated into tissues outside of the intestinal lumen. Virtual-slicing by means of 2D XRF tomography, combined with holotomography, indicated presumable presence of individual NP aggregates inside the uterus and within embryos. |
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Wos |
000414887000041 |
Publication Date |
2017-10-10 |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
13 |
Open Access |
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Notes |
; This study has been funded by the Norwegian Research Council through its Centre of Excellence (CoE) funding scheme (Project 223268/F50). We gratefully acknowledge ESRF and DESY for granting beamtime and Karl Andreas Jensen for performing ICPMS analysis. We thank Erica Maremonti for supplying the phase-contrast image used in Figure ^1A. ; |
Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:147383 |
Serial |
5520 |
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Author |
Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K. |
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Title |
Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
89 |
Issue |
89 |
Pages |
3326-3334 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken. |
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Place of Publication |
Washington, D.C. |
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Wos |
000397478300015 |
Publication Date |
2017-02-23 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
7 |
Open Access |
OpenAccess |
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Notes |
; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government, department EWI. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; |
Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ lucian @ c:irua:140886 |
Serial |
4451 |
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Author |
Aghaei, M.; Lindner, H.; Bogaerts, A. |
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Title |
Ion Clouds in the Inductively Coupled Plasma Torch: A Closer Look through Computations |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
88 |
Issue |
88 |
Pages |
8005-8018 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
We have computationally investigated the introduction of copper elemental particles in an inductively coupled plasma torch connected to a sampling cone, including for the first time the ionization of the sample. The sample is inserted as liquid particles, which are followed inside the entire torch, i.e., from the injector inlet up to the ionization and reaching the sampler. The spatial position of the ion clouds inside the torch as well as detailed information on the copper species fluxes at the position of the sampler orifice and the exhausts of the torch are provided. The effect of on- and off-axis injection is studied. We clearly show that the ion clouds of on-axis injected material are located closer to the sampler with less radial diffusion. This guarantees a higher transport efficiency through the sampler cone. Moreover, our model reveals the optimum ranges of applied power and flow rates, which ensure the proper position of ion clouds inside the torch, i.e., close enough to the sampler to increase the fraction that can enter the mass spectrometer and with minimum loss of material toward the exhausts as well as a sufficiently high plasma temperature for efficient ionization. |
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Address |
Research Group PLASMANT, Chemistry Department, University of Antwerp , Universiteitsplein 1, 2610 Antwerp, Belgium |
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English |
Wos |
000381654800020 |
Publication Date |
2016-07-26 |
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ISSN |
0003-2700 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
9 |
Open Access |
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Notes |
The authors gratefully acknowledge financial support from the Fonds voor Wetenschappelijk Onderzoek (FWO), Grant Number 6713. The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI), and the UA. |
Approved |
Most recent IF: 6.32 |
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Call Number |
PLASMANT @ plasmant @ c:irua:135644 |
Serial |
4293 |
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Author |
Ayalew, E.; Janssens, K.; De Wael, K. |
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Title |
Unraveling the reactivity of minium towards bicarbonate and the role of lead oxides therein |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
88 |
Issue |
3 |
Pages |
1564-1569 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Understanding the reactivity of (semiconductor) pigments provides vital information on how to improve conservation strategies for works of art in order to avoid rapid degradation of the pigments. This study focuses on the photoactivity of minium (Pb3O4), a semiconductor pigment, that gives rise to strong discoloration phenomena upon exposure to various environmental conditions. To demonstrate its photoactivity, an electrochemical setup with minium-modified graphite electrode (C|Pb3O4) was used. It is confirmed that minium is a p-type semiconductor which is photoactive during illumination and becomes inactive in the dark. Raman measurements confirm the formation of the degradation products. The photoactivity of a semiconductor pigment is partly defined by the presence of lead oxide (PbO) impurities; these introduce new states in the original band gap. It will be experi-mentally evidenced that the presence of PbO particles in minium leads to an upward shift of the valence band that reduces the band gap. Thus, upon photoexcitation, the electron/hole separation is more easily initialized. The PbO/Pb3O4 composite electrodes demonstrate a higher reductive photocurrent compared to the photocurrent registered at pure PbO or Pb3O4 modified electrodes. Upon exposure to light with energy close to and above the band gap, electrons are excited from the valence band to the conduction band to initialize the reduction of Pb(IV) to Pb(II), resulting in the initial formation of PbO. However in the presence of bicarbonate ions, a significantly higher photoreduction current is recorded since the PbO reacts further to form hydrocerussite. Therefore the presence of bicarbonates in the environment stimulates the photodecomposition process of minium and plays an important role in the degradation process. |
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Wos |
000369471100014 |
Publication Date |
2015-12-31 |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
9 |
Open Access |
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Notes |
; The authors acknowledge Sanne Aerts from the Laboratory of Adsorption and Catalysis (LADCA) of the University of Antwerp for her help with the UV-vis-DR. Financial support from the SOLARPAINT BOF-GOA project (University of Antwerp Research Council) is acknowledged. The authors are also indebted to F. Vanmeert for performing the XRD measurements. ; |
Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:129963 |
Serial |
5888 |
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Author |
Ranjbari, E.; Hadjmohammadi, M.R.; Kiekens, F.; De Wael, K. |
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Title |
Mixed hemi/ad-micelle sodium dodecyl sulfate-coated magnetic iron oxide nanoparticles for the efficient removal and trace determination of rhodamine-B and rhodamine-6G |
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A1 Journal article |
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Year |
2015 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
87 |
Issue |
15 |
Pages |
7894-7901 |
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Keywords |
A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Mixed hemi/ad-micelle sodium dodecyl sulfate (SDS)-coated magnetic iron oxide nanoparticles (MHAMS-MIONPs) were used as an efficient adsorbent for both removal and preconcentration of two important carcinogenic xanthine dyes named rhodamine-B (RB) and rhodamine-6G (RG). To gain insight in the configuration of SDS molecules on the surface of MIONPs, zeta potential measurements were performed in different [SDS]/[MIONP] ratios. Zeta potential data indicated that mixed hemi/ad-micelle MHAM was formed in [SDS]/[MIONP] ratios over the range of 1.1 to 7.3. Parameters affecting the adsorption of dyes were optimized as removal efficiency by one variable at-a-time and response surface methodology; the obtained removal efficiencies were ∼100%. Adsorption kinetic and equilibrium studies, under the optimum condition (pH = 2; amount of MIONPs = 87.15 mg; [SDS]/[MIONP] ratio = 2.9), showed that adsorption of both dyes are based on the pseudo-second-order and the Langmuir isotherm models, respectively. The maximum adsorption capacities for RB and RG were 385 and 323 mg g1, respectively. MHAMS-MIONPs were also applied for extraction of RB and RG. Under optimum conditions (pH = 2; amount of damped MHAMS-MIONPs = 90 mg; eluent solvent volume = 2.6 mL of 3% acetic acid in acetonitrile), extraction recoveries for 0.5 mg L1 of RB and RG were 98% and 99%, with preconcentration factors of 327 and 330, respectively. Limit of detection obtained for rhodamine dyes were <0.7 ng mL1. Finally, MHAMS-MIONPs were successfully applied for both removal and trace determination of RB and RG in environmental and wastewater samples. |
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Wos |
000359277900056 |
Publication Date |
2015-07-08 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
36 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 6.32; 2015 IF: 5.636 |
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Call Number |
UA @ admin @ c:irua:126583 |
Serial |
5730 |
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Author |
Khan, S.U.; Trashin, S.; Beltran, V.; Korostei, Y.S.; Pelmus, M.; Gorun, S.M.; Dubinina, T., V.; Verbruggen, S.W.; De Wael, K. |
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Title |
Photoelectrochemical behavior of phthalocyanine-sensitized TiO₂ in the presence of electron-shuttling mediators |
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A1 Journal article |
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Year |
2022 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
94 |
Issue |
37 |
Pages |
12723-12731 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Abstract |
Dye-sensitized TiO(2 )has found many applications for dye sensitized solar cells (DSSC), solar-to-chemical energy conversion, water/air purification systems, and (electro)chemical sensors. We report an electrochemical system for testing dye-sensitized materials that can be utilized in photoelectrochemical (PEC) sensors and energy conversion. Unlike related systems, the reported system does not require a direct electron transfer from semiconductors to electrodes. Rather, it relies on electron shuttling by redox mediators. A range of model photocatalytic materials were prepared using three different TiO2 materials (P25, P90, and PC500) and three sterically hindered phthalocyanines (Pcs) with electron-rich tert-butyl substituents (t-Bu4PcZn, t-Bu4PcAlCl, and t-Bu4PcH2). The materials were compared with previously developed TiO(2 )modified by electron-deficient, also sterically hindered fluorinated phthalocyanine F64PcZn, a singlet oxygen (O-1(2)) producer, as well as its metal-free derivative, F64PcH2. The PEC activity depended on the redox mediator, as well as the type of TiO2 and Pc. By comparing the responses of one-electron shuttles, such as K4Fe(CN)(4), and O-1(2)-reactive electron shuttles, such as phenol, it is possible to reveal the action mechanism of the supported photosensitizers, while the overall activity can be assessed using hydroquinone. t-Bu4PcAlCl showed significantly lower blank responses and higher specific responses toward chlorophenols compared to t-Bu4PcZn due to the electron-withdrawing effect of the Al3+ metal center. The combination of reactivity insights and the need for only microgram amounts of sensing materials renders the reported system advantageous for practical applications. |
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Wos |
000855284300001 |
Publication Date |
2022-09-12 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.4 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 7.4 |
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Call Number |
UA @ admin @ c:irua:190602 |
Serial |
7190 |
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Author |
Girard-Sahun, F.; Lefrancois, P.; Badets, V.; Arbault, S.; Clement, F. |
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Title |
Direct sensing of superoxide and its relatives reactive oxygen and nitrogen species in phosphate buffers during cold atmospheric plasmas exposures |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
94 |
Issue |
14 |
Pages |
5555-5565 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
This study aims at sensing in situ reactive oxygen and nitrogen species (RONS) and specifically superoxide anion (O-2(center dot-)) in aqueous buffer solutions exposed to cold atmospheric plasmas (CAPs). CAPs were generated by ionizing He gas shielded with variable N-2/O-2 mixtures. Thanks to ultramicroelectrodes protected against the high electric fields transported by the ionization waves of CAPs, the production of superoxide and several RONS was electrochemically directly detected in liquids during their plasma exposure. Complementarily, optical emissive spectroscopy (OES) was used to study the plasma phase composition and its correlation with the chemistry in the exposed liquid. The specific production of O-2(center dot-), a biologically reactive redox species, was analyzed by cyclic voltammetry (CV), in both alkaline (pH 11), where the species is fairly stable, and physiological (pH 7.4) conditions, where it is unstable. To understand its generation with respect to the plasma chemistry, we varied the shielding gas composition of CAPs to directly impact on the RONS composition at the plasma-liquid interface. We observed that the production and accumulation of RONS in liquids, including O(2)(center dot-)depends on the plasma composition, with N-2-based shieldings providing the highest superoxide concentrations (few 10s of micromolar at most) and of its derivatives (hundreds of micromolar). In situ spectroscopic and electrochemical analyses provide a high resolution kinetic and quantitative understanding of the interactions between CAPs and physiological solutions for biomedical applications. |
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Place of Publication |
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Editor |
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Language |
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Wos |
000805334400013 |
Publication Date |
2022-03-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
7.4 |
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 7.4 |
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| |
Call Number |
UA @ admin @ c:irua:189093 |
Serial |
7143 |
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| Permanent link to this record |
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Author |
Neven, L.; Barich, H.; Ching, H.Y.V.; Khan, S.U.; Colomier, C.; Patel, H.H.; Gorun, S.M.; Verbruggen, S.; Van Doorslaer, S.; De Wael, K. |
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Title |
Correlation between the fluorination degree of perfluorinated zinc phthalocyanines, their singlet oxygen generation ability, and their photoelectrochemical response for phenol sensing |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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| |
Volume |
94 |
Issue |
13 |
Pages |
5221-5230 |
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Keywords |
A1 Journal article; Organic synthesis (ORSY); Sustainable Energy, Air and Water Technology (DuEL); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Abstract |
Electron-withdrawing perfluoroalkyl peripheral groups grafted on phthalocyanine (Pc) macrocycles improve their single-site isolation, solubility, and resistance to self-oxidation, all beneficial features for catalytic applications. A high degree of fluorination also enhances the reducibility of Pcs and could alter their singlet oxygen (1O2) photoproduction. The ethanol/toluene 20:80 vol % solvent mixture was found to dissolve perfluorinated FnPcZn complexes, n = 16, 52, and 64, and minimize the aggregation of the sterically unencumbered F16PcZn. The 1O2 production ability of FnPcZn complexes was examined using 9,10-dimethylanthracene (DMA) and 2,2,6,6-tetramethylpiperidine (TEMP) in combination with UV–vis and electron paramagnetic resonance (EPR) spectroscopy, respectively. While the photoreduction of F52PcZn and F64PcZn in the presence of redox-active TEMP lowered 1O2 production, DMA was a suitable 1O2 trap for ranking the complexes. The solution reactivity was complemented by solid-state studies via the construction of photoelectrochemical sensors based on TiO2-supported FnPcZn, FnPcZn|TiO2. Phenol photo-oxidation by 1O2, followed by its electrochemical reduction, defines a redox cycle, the 1O2 production having been found to depend on the value of n and structural features of the supported complexes. Consistent with solution studies, F52PcZn was found to be the most efficient 1O2 generator. The insights on reactivity testing and structural–activity relationships obtained may be useful for designing efficient and robust sensors and for other 1O2-related applications of FnPcZn. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000786254500002 |
Publication Date |
2022-03-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.4 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 7.4 |
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Call Number |
UA @ admin @ c:irua:187522 |
Serial |
7141 |
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| Permanent link to this record |
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Author |
Alvarez-Martin, A.; Newsome, G.A.; Janssens, K. |
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Title |
High-resolution mass spectrometry and nontraditional mass defect analysis of brominated historical pigments |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
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| |
Volume |
93 |
Issue |
44 |
Pages |
14851-14858 |
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| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp X-ray Imaging and Spectroscopy (AXIS) |
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Abstract |
The implementation of high-resolution mass spectrometry systems offers new possibilities for the analysis of complex art samples such as historical oil paintings. However, these multicomponent systems generate large and complex data sets that require advanced visualization tools to aid interpretation, especially when no chromatographic separation is performed. In the context of this research, it was crucial to propose a data analysis tool to identify the products generated during the synthesis, drying, and aging of historical pigments. This study reports for the first time a nontraditional mass defect analysis of oil paint samples containing a fugitive brominated-organic pigment, eosin or geranium lake, by using direct infusion electrospray ionization in combination with a high-resolution Orbitrap mass spectrometer. The use of nontraditional Kendrick mass defect plots is presented in this study as a processing and visualization tool to recognize brominated species based on their specific mass defect and isotope pattern. The results demonstrate that this approach could provide valuable molecular compositional information on the degradation pathways of this pigment. We anticipate that mass defect analysis will become highly relevant in future degradation studies of many more historical organic pigments. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000718171600037 |
Publication Date |
2021-10-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:182347 |
Serial |
8038 |
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| Permanent link to this record |
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Author |
Trashin, S.; Morales-Yánez, F.; Thiruvottriyur Shanmugam, S.; Paredis, L.; Carrión, E.N.; Sariego, I.; Muyldermans, S.; Polman, K.; Gorun, S.M.; De Wael, K. |
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Title |
Nanobody-based immunosensor detection enhanced by photocatalytic-electrochemical redox cycling |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
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| |
Volume |
93 |
Issue |
40 |
Pages |
13606-13614 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Abstract |
Detection of antigenic biomarkers present in trace amounts is of crucial importance for medical diagnosis. A parasitic disease, human toxocariasis, lacks an adequate diagnostic method despite its worldwide occurrence. The currently used serology tests may stay positive even years after a possibly unnoticed infection, whereas the direct detection of a re-infection or a still active infection remains a diagnostic challenge due to the low concentration of circulating parasitic antigens. We report a time-efficient sandwich immunosensor using small recombinant single-domain antibodies (nanobodies) derived from camelid heavy-chain antibodies specific to Toxocara canis antigens. An enhanced sensitivity to pg/mL levels is achieved by using a redox cycle consisting of a photocatalytic oxidation and electrochemical reduction steps. The photocatalytic oxidation is achieved by a photosensitizer generating singlet oxygen (1O2) that, in turn, readily reacts with p-nitrophenol enzymatically produced under alkaline conditions. The photooxidation produces benzoquinone that is electrochemically reduced to hydroquinone, generating an amperometric response. The light-driven process could be easily separated from the background, thus making amperometric detection more reliable. The proposed method for detection of the toxocariasis antigen marker shows superior performances compared to other detection schemes with the same nanobodies and outperforms by at least two orders of magnitude the assays based on regular antibodies, thus suggesting new opportunities for electrochemical immunoassays of challenging low levels of antigens. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000708550500025 |
Publication Date |
2021-09-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:181795 |
Serial |
8290 |
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| Permanent link to this record |
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Author |
Aghaei, M.; Bogaerts, A. |
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Title |
Flowing Atmospheric Pressure Afterglow for Ambient Ionization: Reaction Pathways Revealed by Modeling |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
93 |
Issue |
17 |
Pages |
6620-6628 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
We describe the plasma chemistry in a helium flowing atmospheric pressure afterglow (FAPA) used for analytical spectrometry, by means of a quasione-dimensional (1D) plasma chemical kinetics model. We study the effect of typical impurities present in the feed gas, as well as the afterglow in ambient humid air. The model provides the species density profiles in the discharge and afterglow regions and the chemical pathways. We demonstrate that H, N, and O atoms are formed in the discharge region, while the dominant reactive neutral species in the afterglow are O3 and NO. He* and He2* are responsible for Penning ionization of O2, N2, H2O, H2, and N, and especially O and H atoms. Besides, He2+ also contributes to ionization of N2, O2, H2O, and O through charge transfer reactions. From the pool of ions created in the discharge, NO+ and (H2O)3H+ are the dominant ions in the afterglow. Moreover, negatively charged clusters, such as NO3H2O− and NO2H2O−, are formed and their pathway is discussed as well. Our model predictions are in line with earlier observations in the literature about the important reagent ions and provide a comprehensive overview of the underlying pathways. The model explains in detail why helium provides a high analytical sensitivity because of high reagent ion formation by both Penning ionization and charge transfer. Such insights are very valuable for improving the analytical performance of this (and other) ambient desorption/ionization source(s). |
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Corporate Author |
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Place of Publication |
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Wos |
000648505900008 |
Publication Date |
2021-05-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
Fonds Wetenschappelijk Onderzoek, 6713 ; The authors gratefully acknowledge financial support from the Fonds voor Wetenschappelijk Onderzoek (FWO) grant number 6713. The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (Department EWI), and the UA. The authors also thank J. T. Shelley for providing experimental data for the gas velocity behind the anode disk and before the mass spectrometer interface, to validate our model. |
Approved |
Most recent IF: 6.32 |
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Call Number |
PLASMANT @ plasmant @c:irua:178126 |
Serial |
6762 |
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Author |
Monico, L.; Cotte, M.; Vanmeert, F.; Amidani, L.; Janssens, K.; Nuyts, G.; Garrevoet, J.; Falkenberg, G.; Glatzel, P.; Romani, A.; Miliani, C. |
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Title |
Damages induced by synchrotron radiation-based X-ray microanalysis in chrome yellow paints and related Cr-compounds : assessment, quantification, and mitigation strategies |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
92 |
Issue |
20 |
Pages |
14164-14173 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Synchrotron radiation (SR)-based X-ray methods are powerful analytical tools for several purposes. They are widely used to probe the degradation mechanisms of inorganic artists' pigments in paintings, including chrome yellows (PbCr1-xSxO4; 0 <= x <= 0.8), a class of compounds often found in Van Gogh masterpieces. However, the high intensity and brightness of SR beams raise important issues regarding the potential damage inflicted on the analyzed samples. A thorough knowledge of the SR X-ray sensitivity of each class of pigment in the painting matrix is therefore required to find analytical strategies that seek to minimize the damage for preserving the integrity of the analyzed samples and to avoid data misinterpretation. Here, we employ a combination of Cr K-edge X-ray absorption near-edge structure spectroscopy, Cr-K-beta X-ray emission spectroscopy, and X-ray diffraction to monitor and quantify the effects of SR X-rays on the stability of chrome yellows and related Cr compounds and to define mitigation strategies. We found that the SR X-ray beam exposure induces changes in the oxidation state and local coordination environment of Cr ions and leads to a loss of the compound's crystalline structure. The extent of X-ray damage depends on some intrinsic properties of the samples (chemical composition of the pigment and the presence/absence and nature of the binder). It can be minimized by optimizing the overall fluence/dose released to the samples and by working in vacuum and under cryogenic conditions. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Wos |
000584418100072 |
Publication Date |
2020-09-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.4 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 7.4; 2020 IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:174363 |
Serial |
7754 |
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| Permanent link to this record |
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Author |
Wiorek, A.; Parrilla, M.; Cuartero, M.; Crespo, G.A. |
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Title |
Epidermal patch with glucose biosensor : pH and temperature correction toward more accurate sweat analysis during sport practice |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
92 |
Issue |
14 |
Pages |
10153-10161 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
We present an epidermal patch for glucose analysis in sweat incorporating for the first time pH and temperature correction according to local dynamic fluctuations in sweat during on-body tests. This sort of correction is indeed the main novelty of the paper, being crucial toward reliable measurements in every sensor based on an enzymatic element whose activity strongly depends on pH and temperature. The results herein reported for corrected glucose detection during on-body measurements are supported by a two-step validation protocol: with the biosensor operating off- and on-bodily, correlating the results with UV-vis spectrometry and/or ion chromatography. Importantly, the wearable device is a flexible skin patch that comprises a microfluidic cell designed with a sweat collection zone coupled to a fluidic channel in where the needed electrodes are placed: glucose biosensor, pH potentiometric electrode and a temperature sensor. The glucose biosensor presents a linear range of response within the expected physiological levels of glucose in sweat (10-200 mu M), and the calibration parameters are dynamically adjusted to any change in pH and temperature during the sport practice by means of a new “correction approach”. In addition, the sensor displays a fast response time, appropriate selectivity, and excellent reversibility. A total of 9 validated on-body tests are presented: the outcomes revealed a great potential of the wearable glucose sensor toward the provision of reliable physiological data linked to individuals during sport activity. In particular, the developed “correction approach” is expected to impact into the next generation of wearable devices that digitalize physiological activities through chemical information in a trustable manner for both sport and healthcare applications. |
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Place of Publication |
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Wos |
000554986200089 |
Publication Date |
2020-06-26 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.4 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 7.4; 2020 IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:175265 |
Serial |
7931 |
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Author |
Khalilov, U.; Bogaerts, A.; Neyts, E.C. |
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Title |
Toward the Understanding of Selective Si Nano-Oxidation by Atomic Scale Simulations |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Accounts of chemical research |
Abbreviated Journal |
Accounts Chem Res |
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Volume |
50 |
Issue |
50 |
Pages |
796-804 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
The continuous miniaturization of nanodevices, such as transistors, solar cells, and optical fibers, requires the controlled synthesis of (ultra)thin gate oxides (<10 nm), including Si gate-oxide (SiO2) with high quality at the atomic scale. Traditional thermal growth of SiO2 on planar Si surfaces, however, does not allow one to obtain such ultrathin oxide due to either the high oxygen diffusivity at high temperature or the very low sticking ability of incident oxygen at low temperature. Two recent techniques, both operative at low (room) temperature, have been put forward to overcome these obstacles: (i) hyperthermal oxidation of planar Si surfaces and (ii) thermal or plasma-assisted oxidation of nonplanar Si surfaces, including Si nanowires (SiNWs). These nanooxidation processes are, however, often difficult to study experimentally, due to the key intermediate processes taking place on the nanosecond time scale.
In this Account, these Si nano-oxidation techniques are discussed from a computational point of view and compared to both hyperthermal and thermal oxidation experiments, as well as to well-known models of thermal oxidation, including the Deal−Grove, Cabrera−Mott, and Kao models and several alternative mechanisms. In our studies, we use reactive molecular dynamics (MD) and hybrid MD/Monte Carlo simulation techniques, applying the Reax force field. The incident energy of oxygen species is chosen in the range of 1−5 eV in hyperthermal oxidation of planar Si surfaces in order to prevent energy-induced damage. It turns out that hyperthermal growth allows for two growth modes, where the ultrathin oxide thickness depends on either (1) only the kinetic energy of the incident oxygen species at a growth temperature below Ttrans = 600 K, or (2) both the incident energy and the growth temperature at a growth temperature above Ttrans. These modes are specific to such ultrathin oxides, and are not observed in traditional thermal oxidation, nor theoretically considered by already existing models. In the case of thermal or plasma-assisted oxidation of small Si nanowires, on the other hand, the thickness of the ultrathin oxide is a function of the growth temperature and the nanowire diameter. Below Ttrans, which varies with the nanowire diameter, partially oxidized SiNW are formed, whereas complete oxidation to a SiO2 nanowire occurs only above Ttrans. In both nano-oxidation processes at lower temperature (T < Ttrans), final sandwich c-Si|SiOx|a-SiO2 structures are obtained due to a competition between overcoming the energy barrier to penetrate into Si subsurface layers and the compressive stress (∼2−3 GPa) at the Si crystal/oxide interface. The overall atomic-simulation results strongly indicate that the thickness of the intermediate SiOx (x < 2) region is very limited (∼0.5 nm) and constant irrespective of oxidation parameters. Thus, control over the ultrathin SiO2 thickness with good quality is indeed possible by accurately tuning the oxidant energy, oxidation temperature and surface curvature.
In general, we discuss and put in perspective these two oxidation mechanisms for obtaining controllable ultrathin gate-oxide films, offering a new route toward the fabrication of nanodevices via selective nano-oxidation. |
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Place of Publication |
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Language |
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Wos |
000399859800016 |
Publication Date |
2017-04-18 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0001-4842 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
20.268 |
Times cited |
5 |
Open Access |
OpenAccess |
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Notes |
Fonds Wetenschappelijk Onderzoek, 12M1315N ; |
Approved |
Most recent IF: 20.268 |
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Call Number |
PLASMANT @ plasmant @ c:irua:142638 |
Serial |
4561 |
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| Permanent link to this record |
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Author |
Albrecht, W.; Van Aert, S.; Bals, S. |
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Title |
Three-Dimensional Nanoparticle Transformations Captured by an Electron Microscope |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Accounts Of Chemical Research |
Abbreviated Journal |
Accounts Chem Res |
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Volume |
54 |
Issue |
5 |
Pages |
1189-1199 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000626269900011 |
Publication Date |
2021-03-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0001-4842 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
20.268 |
Times cited |
12 |
Open Access |
OpenAccess |
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Notes |
The authors acknowledge funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Consolidator Grants No. 815128–REALNANO and No. 770887–PICOMETRICS), the Research Foundation Flanders (FWO, G.0267.18N), and the European Commission (EUSMI). The authors furthermore acknowledge funding from the European Union’s Horizon 2020 research and innovation program, ESTEEM3. The authors also acknowledge contributions from all co-workers that have contributed over the years: Thomas Altantzis, Annick De Backer, Joost Batenburg and co-workers, Armand Béché, Eva Bladt, Lewys Jones and co-workers, Luis Liz-Marzán and co-workers, Ivan Lobato, Thais Milagres de Oliveira, Peter Nellist and co-workers, Hugo Pérez Garza and co-workers, Alexander Skorikov, Sara Skrabalak and co-workers, Sandra Van Aert, Alfons van Blaaderen and co-workers, Hans Vanrompay, Staf Van Tendeloo, and Johan Verbeeck.; sygmaSB; |
Approved |
Most recent IF: 20.268 |
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| |
Call Number |
EMAT @ emat @c:irua:177644 |
Serial |
6752 |
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| Permanent link to this record |
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Author |
Hamidi-Asl, E.; Daems, D.; De Wael, K.; Van Camp, G.; Nagels, L.J. |
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Title |
Concentration related response potentiometric titrations to study the interaction of small molecules with large biomolecules |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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| |
Volume |
86 |
Issue |
24 |
Pages |
12243-12249 |
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| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
In the present article, the utility of a special potentiometric titration approach for recognition and calculation of biomolecule/small molecule interactions is reported. This approach is fast, sensitive, reproducible and inexpensive in comparison to the other methods for the determination of the association constant values (Ka) and the interaction energies (ΔG). The potentiometric titration measurement is based on the use of a classical polymeric membrane indicator electrode in a solution of the small molecule ligand. The biomolecule is used as a titrant. The potential is measured versus a reference electrode and transformed to a concentration related signal over the entire concentration interval, also at low concentrations, where the mV (y-axis) versus logcanalyte (x-axis) potentiometric calibration curve is not linear. In the procedure, the Ka is calculated for the interaction of cocaine with a cocaine binding aptamer and with an anti-cocaine antibody. To study the selectivity and cross-reactivity, other oligonucleotides and aptamers are tested, as well as other small ligand molecules such as tetrakis (4-chlorophenyl)borate, metergoline, lidocaine, and bromhexine. The calculated Ka compared favorably to the value reported in the literature using SPR. The potentiometric titration approach called Concentration related Response Potentiometry, is used to study molecular interaction for 7 macromolecular target molecules and 4 small molecule ligands. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000346683900048 |
Publication Date |
2014-11-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
10 |
Open Access |
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Notes |
; Financial support for this work was provided by the University of Antwerp by granting L.J.N., K.D.W, G.V.C., and Ronny Blust a POC interdisciplinary research project. ; |
Approved |
Most recent IF: 6.32; 2014 IF: 5.636 |
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| |
Call Number |
UA @ admin @ c:irua:120164 |
Serial |
5548 |
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| Permanent link to this record |
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Author |
Hoffman, B.M.; Lukoyanov, D.; Yang, Z.-Y.; Dean, D.R.; Seefeldt, L.C. |
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Title |
Mechanism of Nitrogen Fixation by Nitrogenase: The Next Stage |
Type |
A1 Journal Article |
| |
Year |
2014 |
Publication |
Chemical Reviews |
Abbreviated Journal |
Chem. Rev. |
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| |
Volume |
114 |
Issue |
8 |
Pages |
4041-4062 |
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Keywords |
A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; |
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Abstract |
Ammonia is a crucial nutrient used for plant growth and as a building block in pharmaceutical and chemical industry, produced via nitrogen fixation of the ubiquitous atmospheric N2. Current industrial ammonia production relies heavily on fossil resources, but a lot of work is put into developing non-fossil based pathways. Among these is the use of nonequilibrium plasma. In this work, we investigated water vapor as H source for nitrogen fixation into NH3 by non-equilibrium plasma. The highest selectivity towards NH3 was observed with low amounts of added H2O vapor, but the highest production rate was reached at high H2O vapor. |
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Wos |
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Publication Date |
2014-04-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0009-2665 |
ISBN |
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Additional Links |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
We would like to thank Sylvia Dewilde (Department of Biomedical Sciences) for providing analytical equipment. |
Approved |
no |
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Call Number |
PLASMANT @ plasmant @ |
Serial |
6337 |
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| Permanent link to this record |
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Author |
Michiels, R.; Engelmann, Y.; Bogaerts, A. |
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Title |
Plasma Catalysis for CO2Hydrogenation: Unlocking New Pathways toward CH3OH |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
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Volume |
124 |
Issue |
47 |
Pages |
25859-25872 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Movement Antwerp (MOVANT) |
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Abstract |
We developed a microkinetic model to reveal the effects of plasma-generated radicals, intermediates, and vibrationally excited species on the catalytic hydrogenation of CO2 to CH3OH on a Cu(111) surface. As a benchmark, we first present the mechanisms of thermal catalytic CH3OH formation. Our model predicts that the reverse water-gas shift reaction followed by CO hydrogenation, together with the formate path, mainly contribute to CH3OH formation in thermal catalysis. Adding plasma-generated radicals and intermediates results in a higher CH3OH turnover frequency (TOF) by six to seven orders of magnitude, showing the potential of plasma-catalytic CO2 hydrogenation into CH3OH, in accordance with the literature. In addition, CO2 vibrational excitation further increases the CH3OH TOF, but the effect is limited due to relatively low vibrational temperatures under typical plasma catalysis conditions. The predicted increase in CH3OH formation by plasma catalysis is mainly attributed to the increased importance of the formate path. In addition, the conversion of plasma-generated CO to HCO* and subsequent HCOO* or H2CO* formation contribute to CH3OH formation. Both pathways bypass the HCOO* formation from CO2, which is the main bottleneck in the process. Hence, our model points toward the important role of CO, but also O, OH, and H radicals, as they influence the reactions that consume CO2 and CO. In addition, our model reveals that the H pressure should not be smaller than ca. half of the O pressure in the plasma as this would cause O* poisoning, which would result in very small product TOFs. Thus, plasma conditions should be targeted with a high CO and H content as this is favorable for CH3OH formation, while the O content should be minimized. |
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Corporate Author |
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Place of Publication |
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Wos |
000595545800023 |
Publication Date |
2020-11-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
|
Open Access |
Not_Open_Access: Available from 15.07.2021 |
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Notes |
Universiteit Antwerpen; Fonds Wetenschappelijk Onderzoek, 1114921N ; H2020 European Research Council, 810182 ; We acknowledge the financial support from the Fund for Scientific Research (FWO-Vlaanderen; grant ID 1114921N) and from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 810182 − SCOPE ERC Synergy project) as well as from the DOC-PRO3 and the TOPBOF projects of the University of Antwerp. |
Approved |
Most recent IF: 3.7; 2020 IF: 4.536 |
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Call Number |
PLASMANT @ plasmant @c:irua:173864 |
Serial |
6443 |
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| Permanent link to this record |
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Author |
Ghasemitarei, M.; Privat-Maldonado, A.; Yusupov, M.; Rahnama, S.; Bogaerts, A.; Ejtehadi, M.R. |
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Title |
Effect of Cysteine Oxidation in SARS-CoV-2 Receptor-Binding Domain on Its Interaction with Two Cell Receptors: Insights from Atomistic Simulations |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Journal Of Chemical Information And Modeling |
Abbreviated Journal |
J Chem Inf Model |
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Volume |
62 |
Issue |
1 |
Pages |
129-141 |
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Keywords |
A1 Journal article; Pharmacology. Therapy; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Binding of the SARS-CoV-2 S-glycoprotein to cell receptors is vital for the entry of the virus into cells and subsequent infection. ACE2 is the main cell receptor for SARS-CoV-2, which can attach to the C-terminal receptor-binding domain (RBD) of the SARS-CoV-2 S-glycoprotein. The GRP78 receptor plays an anchoring role, which attaches to the RBD and increases the chance of other RBDs binding to ACE2. Although high levels of reactive oxygen and nitrogen species (RONS) are produced during viral infections, it is not clear how they affect the RBD structure and its binding to ACE2 and GRP78. In this research, we apply molecular dynamics simulations to study the effect of oxidation of the highly reactive cysteine (Cys) amino acids of the RBD on its binding to ACE2 and GRP78. The interaction energy of both ACE2 and GRP78 with the whole RBD, as well as with the RBD main regions, is compared in both the native and oxidized RBDs. Our results show that the interaction energy between the oxidized RBD and ACE2 is strengthened by 155 kJ/mol, increasing the binding of the RBD to ACE2 after oxidation. In addition, the interaction energy between the RBD and GRP78 is slightly increased by 8 kJ/mol after oxidation, but this difference is not significant. Overall, these findings highlight the role of RONS in the binding of the SARS-CoV-2 S-glycoprotein to host cell receptors and suggest an alternative mechanism by which RONS could modulate the entrance of viral particles into the cells. |
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Corporate Author |
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Wos |
000740019000001 |
Publication Date |
2022-01-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1549-9596 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.6 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
Fonds Wetenschappelijk Onderzoek, 1200219N ; Binding of the SARS-CoV-2 S-glycoprotein to cell receptors is vital for the entry of the virus into cells and subsequent infection. ACE2 is the main cell receptor for SARS-CoV-2, which can attach to the C-terminal receptor-binding domain (RBD) of the SARS-CoV-2 S-glycoprotein. The GRP78 receptor plays an anchoring role, which attaches to the RBD and increases the chance of other RBDs binding to ACE2. Although high levels of reactive oxygen and nitrogen species (RONS) are produced during viral infections, it is not clear how they affect the RBD structure and its binding to ACE2 and GRP78. In this research, we apply molecular dynamics simulations to study the effect of oxidation of the highly reactive cysteine (Cys) amino acids of the RBD on its binding to ACE2 and GRP78. The interaction energy of both ACE2 and GRP78 with the whole RBD, as well as with the RBD main regions, is compared in both the native and oxidized RBDs. Our results show that the interaction energy between the oxidized RBD and ACE2 is strengthened by 155 kJ/mol, increasing the binding of the RBD to ACE2 after oxidation. In addition, the interaction energy between the RBD and GRP78 is slightly increased by 8 kJ/mol after oxidation, but this difference is not significant. Overall, these findings highlight the role of RONS in the binding of the SARS-CoV-2 S-glycoprotein to host cell receptors and suggest an alternative mechanism by which RONS could modulate the entrance of viral particles into the cells. |
Approved |
Most recent IF: 5.6 |
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Call Number |
PLASMANT @ plasmant @c:irua:185485 |
Serial |
7050 |
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Author |
Neven, L.; Thiruvottriyur Shanmugam, S.; Rahemi, V.; Trashin, S.; Sleegers, N.; Carrion, E.N.; Gorun, S.M.; De Wael, K. |
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Title |
Optimized photoelectrochemical detection of essential drugs bearing phenolic groups |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
91 |
Issue |
15 |
Pages |
9962-9969 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The World Health Organization (WHO) model “List of Essential Medicines” includes among indispensable medicines antibacterials and pain and migraine relievers. Monitoring their concentration in the environment, while challenging, is important in the context of antibiotic resistance as well as their production of highly toxic compounds via hydrolysis. Traditional detection methods such as high-performance liquid chromatography (HPLC) or LC combined with tandem mass spectrometry or UV-vis spectroscopy are time-consuming, have a high cost, require skilled operators and are difficult to adapt for field operations. In contrast, (electrochemical) sensors have elicited interest because of their rapid response, high selectivity, and sensitivity as well as potential for on-site detection. Previously, we reported a novel sensor system based on a type II photosensitizer, which combines the advantages of enzymatic sensors (high sensitivity) and photoelectrochemical sensors (easy baseline subtraction). Under red-light illumination, the photosensitizer produces singlet oxygen which oxidizes phenolic compounds present in the sample. The subsequent reduction of the oxidized phenolic compounds at the electrode surface gives rise to a quantifiable photocurrent and leads to the generation of a redox cycle. Herein we report the optimization in terms of pH and applied potential of the photoelectrochemical detection of the hydrolysis product of paracetamol, i.e., 4-aminophenol (4-AP), and two antibacterials, namely, cefadroxil (CFD, beta-lactam antibiotic) and doxycycline (DXC, tetracycline antibiotic). The optimized conditions resulted in a detection limit of 0.2 mu mol L-1 for DXC, but in a 10 times higher sensitivity, 20 nmol L-1, for CFD. An even higher sensitivity, 7 nmol L-1, was noted for 4-AP. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Wos |
000480499200086 |
Publication Date |
2019-06-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
2 |
Open Access |
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Notes |
; FWO and UA-BOF are acknowledged for financial support. The Center for Functional Materials of Seton Hall University is thanked for support (S.M.G. and E.N.C.). Joren Van Loon is thanked for the graphical abstract. This research was supported by the medium scale research infrastructure funding Hercules funding (SEM). ; |
Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:161831 |
Serial |
5763 |
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Author |
Drăgan, A.-M.; Parrilla, M.; Feier, B.; Oprean, R.; Cristea, C.; De Wael, K. |
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Title |
Analytical techniques for the detection of amphetamine-type substances in different matrices : a comprehensive review |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Trac-Trends In Analytical Chemistry |
Abbreviated Journal |
Trac-Trend Anal Chem |
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Volume |
145 |
Issue |
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Pages |
116447 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Abstract |
This current review focuses on contributions to amphetamine-type substances (ATS) analysis. This type of synthetic illicit drugs has been increasingly present worldwide reaching 5% of the market on illicit drugs in 2019. The increment of their production in many clandestine laboratories and easy distribution among society are two of the main concerns towards the battle against synthetic drugs. Therefore, the first part of this review details the classification and mechanism of action of ATS in the human body. Second, the pharmacological and toxicological effects of ATS on human health are described to motivate the need of early detection of ATS. Subsequently, the most used laboratory-based and portable methods are presented and critically discussed along the review. Finally, a careful discussion on the advantages and disadvantages of portable techniques employed on the field are addressed as potential tools for on-site ATS detection by law enforcement officers. |
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Place of Publication |
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Wos |
000723747000009 |
Publication Date |
2021-09-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0165-9936; 1879-3142 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.442 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 8.442 |
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Call Number |
UA @ admin @ c:irua:183268 |
Serial |
7460 |
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Author |
Daems, E.; Moro, G.; Campos, R.; De Wael, K. |
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Title |
Mapping the gaps in chemical analysis for the characterisation of aptamer-target interactions |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Trac-Trends In Analytical Chemistry |
Abbreviated Journal |
Trac-Trend Anal Chem |
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Volume |
142 |
Issue |
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Pages |
116311 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Aptamers are promising biorecognition elements with a wide applicability from therapeutics to bio-sensing. However, to successfully use these biomolecules, a complete characterisation of their bindingperformance in the presence of the target is crucial. Several multi-analytical approaches have been re-ported including techniques to describe kinetic and thermodynamic aspects of the aptamer-targetinteraction, and techniques which allow an in-depth understanding of the aptamer-target structures.Recent literature shows the need of a critical data interpretation, a combination of characterisationtechniques and suggests the key role of the characterisation protocol design. Indeed, thefinal applicationof the aptamer should be considered before choosing the characterisation method. All the limitations andcapabilities of the analytical tools in use for aptamer characterisation should be taken into account. Here,we present a critical overview of the current methods and multi-analytical approaches to study aptamer-target binding, aiming to provide researchers with guidelines for the design of characterisation protocols. |
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Place of Publication |
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Language |
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Wos |
000682179000010 |
Publication Date |
2021-04-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0165-9936; 1879-3142 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.442 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 8.442 |
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Call Number |
UA @ admin @ c:irua:179407 |
Serial |
8203 |
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Author |
Parrilla, M.; Joosten, F.; De Wael, K. |
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Title |
Enhanced electrochemical detection of illicit drugs in oral fluid by the use of surfactant-mediated solution |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Sensors And Actuators B-Chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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Volume |
348 |
Issue |
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Pages |
130659 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Abstract |
Illicit drug consumption is a worldwide worrying phenomenon that troubles modern society. For this reason, law enforcement agencies (LEAs) are placing tremendous efforts into tackling the spreading of such substances among our community. New sensing technologies can facilitate the LEAs duties by providing portable and affordable analytical devices. Herein, we present for the first time a sensitive and low-cost electrochemical method, i.e. square-wave adsorptive stripping voltammetry on carbon screen-printed electrodes (SPE), for the detection of five illicit drugs (i.e. cocaine, heroin, 3,4-methylenedioxymethamphetamine, 4-chloro-alpha-pyrrolidinovalerophenone, and ketamine) in oral fluid by the aid of a surfactant. Particularly, the surfactant is adsorbed at the carbon electrode’s surface and yields the adsorption of illicit drug molecules, allowing for an enhanced electrochemical signal in comparison to surfactant-free media. First, the surfactant-mediated behavior is deeply explored at the SPE by cyclic voltammetry, electrochemical impedance spectroscopy, and Fourier-transform infrared spectroscopy. Subsequently, the electrochemical behavior of the five illicit drugs is studied and optimized to render optimal analytical performance. Accordingly, the analytical system exhibited a wide linear concentration range from 1 to 30 µM with sub-micromolar limits of detection and high sensitivity. This performance is similar to other reported electrochemical sensors, but with the advantage of using an unmodified SPE, thus avoiding costly and complex functionalization of the SPE. Finally, the methodology was evaluated in diluted oral fluid samples spiked with illicit drugs. Overall, this work describes a simple, rapid, portable, and sensitive method for the detection of illicit drugs aiming to provide oral fluid testing opportunities to LEAs. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000701915600005 |
Publication Date |
2021-08-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0925-4005 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.401 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 5.401 |
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Call Number |
UA @ admin @ c:irua:181307 |
Serial |
7912 |
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Author |
Parrilla, M.; Montiel, F.N.; Van Durme, F.; De Wael, K. |
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Title |
Derivatization of amphetamine to allow its electrochemical detection in illicit drug seizures |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Sensors And Actuators B-Chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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Volume |
337 |
Issue |
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Pages |
129819 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Amphetamine (AMP) is posing critical issues in our society being one of the most encountered drugs-of-abuse in the current illicit market. The continuous drug production in Europe urges the development of new tools for the rapid on-site determination of illicit drugs such as AMP. However, the direct electrochemical detection of AMP is a challenge because the molecule is non-electroactive at the potential window of conventional graphite SPEs. For this reason, a derivatization step is needed to convert the primary amine into an electroactive oxidizable group. Herein, the rapid electrochemical detection of AMP in seized samples based on the derivatization by 1,2-naphthoquinone-4-sulfonate (NQS) is presented by using square wave voltammetry (SWV) at graphite screen-printed electrodes (SPEs). First, a detailed optimization of the key parameters and the analytical performance is provided. The method showed a sensitivity of 7.9 µA mM-1 within a linear range from 50 to 500 µM, a limit of detection of 22.2 µM, and excellent reproducibility (RSD = 4.3%, n = 5 at 500 µM). Subsequently, the effect of NQS on common cutting agents for the selective detection of AMP is addressed. The comparison of the method with drugs-of-abuse containing secondary and tertiary amines confirms the selectivity of the method. Finally, the concept is applied to quantify AMP in 20 seized samples provided by forensic laboratories, exhibiting an accuracy of 97.3 ± 10.5%. Overall, the fast analysis of samples with the electrochemical profiling of derivatized AMP exhibits a straightforward on-site screening aiming to facilitate the tasks of law enforcement agents in the field. |
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Wos |
000640386500001 |
Publication Date |
2021-03-19 |
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Series Issue |
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Edition |
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ISSN |
0925-4005 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.401 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 5.401 |
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Call Number |
UA @ admin @ c:irua:176353 |
Serial |
7762 |
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Author |
Chizhov, As.; Rumyantseva, Mn.; Drozdov, Ka.; Krylov, Iv.; Batuk, M.; Hadermann, J.; Filatova, Dg.; Khmelevsky, No.; Kozlovsky, Vf.; Maltseva, Ln.; Gaskov, Am. |
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Title |
Photoresistive gas sensor based on nanocrystalline ZnO sensitized with colloidal perovskite CsPbBr3 nanocrystals |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Sensors And Actuators B-Chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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Volume |
329 |
Issue |
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Pages |
129035 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The development of sensor materials of which gas sensitivity activates under light illumination is of great importance for the design of portable gas analyzers with low power consumption. In the present work a ZnO/CsPbBr3 nanocomposite based on nanocrystalline ZnO and colloidal cubic-shaped perovskite CsPbBr3 nanocrystals (NCs) capped by oleic acide and oleylamine was synthesized. The individual materials and obtained nanocomposite are characterized by x-ray diffraction, low-temperature nitrogen adsorption, x-ray photoelectron spectroscopy, high angle annular dark field scanning transmission electron microscopy with energy-dispersive Xray spectroscopy mapping and UV-vis absorption spectroscopy. The spectral dependence of the photoconductivity of the ZnO/CsPbBr3 nanocomposite reveals a well-defined peak that strongly correlates with the its optical absorption spectrum. The nanocomposite ZnO/CsPbBr3 shows enhanced photoresponse under visible light illumination (lambda(max) = 470 nm, 8 mW/cm(2)) in air, oxygen and argone, compared with pure nanocrystalline ZnO. Under periodic illumination in the temperature range of 25-100 degrees C, the ZnO/CsPbBr3 nanocomposite shows a sensor response to 0.5-3.0 ppm NO2, unlike pure nanocrystalline ZnO matrix, which demonstrates sensor sensitivity to NO2 under the same conditions above 100 degrees C. The effects of humidity on the sensor signal and photoresponse are also discussed. |
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Wos |
000612060700009 |
Publication Date |
2020-10-25 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0925-4005 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.401 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
The reported study was funded by RFBR according to the research project N◦ 18-33-01004 and in part by a grant from the St. Petersburg State University – Event 3-2018 (id: 46380300). Element mapping for sensors were supported by M.V. Lomonosov Moscow State University Program of Development (X-ray fluorescence spectrometer Tornado M4 plus). |
Approved |
Most recent IF: 5.401 |
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Call Number |
EMAT @ emat @c:irua:176123 |
Serial |
6707 |
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Author |
Rahemi, V.; Trashin, S.; Hafideddine, Z.; Meynen, V.; Van Doorslaer, S.; De Wael, K. |
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Title |
Enzymatic sensor for phenols based on titanium dioxide generating surface confined ROS after treatment with H2O2 |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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Volume |
283 |
Issue |
283 |
Pages |
343-348 |
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Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Titanium dioxide (TiO2) is a popular material as host matrix for enzymes. We now evidence that TiO2 can accumulate and retain reactive oxygen species after treatment by hydrogen peroxide (H2O2) and support redox cycling of a phenolic analyte between horseradish peroxidase (HRP) and an electrode. The proposed detection scheme is identical to that of second generation biosensors, but the measuring solution requires no dissolved H2O2. This significantly simplifies the analysis and overcomes issues related to H2O2 being present (or generated) in the solution. The modified electrodes showed rapid stabilization of the baseline, a low noise level, fast realization of a steady-state current response, and, in addition, improved sensitivity and limit of detection compared to the conventional approach, i.e. in the presence of H2O2 in the measuring solution. Hydroquinone, 4-aminophenol, and other phenolic compounds were successfully detected at sub-μM concentrations. Particularly, a linear response in the concentration range between 0.025 and 2 μM and LOD of 24 nM was demonstrated for 4-aminophenol. The proposed sensor design goes beyond the traditional concept with three sensors generations offering a new possibility for the development of enzymatic sensors based on peroxidases and the formation of ROS on titania after treatment with H2O2. |
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Wos |
000455854000043 |
Publication Date |
2018-12-10 |
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Series Issue |
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Edition |
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ISSN |
0925-4005 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.401 |
Times cited |
1 |
Open Access |
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Notes |
; The authors thank the University of Antwerp for GOA funding and the Scientific Research-Flanders (FWO) (grant 12T4219N). V. Rahemi is financially supported through a postdoctoral fellowship of the Research Foundation-Flanders (FWO). ; |
Approved |
Most recent IF: 5.401 |
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Call Number |
UA @ admin @ c:irua:155665 |
Serial |
5605 |
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Author |
Rumyantseva, M.N.; Vladimirova, S.A.; Vorobyeva, N.A.; Giebelhaus, I.; Mathur, S.; Chizhov, A.S.; Khmelevsky, N.O.; Aksenenko, A.Y.; Kozlovsky, V.F.; Karakulina, O.M.; Hadermann, J.; Abakumov, A.M.; Gaskov, A.M. |
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Title |
p -CoO x / n -SnO 2 nanostructures: New highly selective materials for H 2 S detection |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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Pages |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Nanostructures p-CoOx/n-SnO2 based on tin oxide nanowires have been prepared by two step CVD technique and characterized in detail by XRD, XRF, XPS, HAADF-STEM imaging and EDX-STEM mapping. Depending on the temperature of decomposition of cobalt complex during the second step of CVD synthesis of nanostructures cobalt oxide forms a coating and/or isolated nanoparticles on SnO2 nanowire surface. It was found that cobalt presents in +2 and +3 oxidation states. The measurements of gas sensor properties have been carried out during exposure to CO (14 ppm), NH3 (21 ppm), and H2S (2 ppm) in dry air. The opposite trends were observed in the effect of cobalt oxide on the SnO2 gas sensitivity when detecting CO or NH3 in comparison to H2S. The decrease of sensor signal toward CO and NH3 was attributed to high catalytic activity of Co3O4 in oxidation of these gases. Contrary, the significant increase of sensor signal in the presence of H2S was attributed to the formation of metallic cobalt sulfide and removal of the barrier between p-CoOx and n-SnO2. This effect provides an excellent selectivity of p-CoOx/n-SnO2 nanostructures in H2S detection. |
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Wos |
000414151800068 |
Publication Date |
2017-08-17 |
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Edition |
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ISSN |
0925-4005 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.401 |
Times cited |
13 |
Open Access |
Not_Open_Access: Available from 10.10.2019
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Notes |
ERA-Net.Plus, 096 FONSENS ; |
Approved |
Most recent IF: 5.401 |
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Call Number |
EMAT @ emat @c:irua:145926 |
Serial |
4710 |
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Author |
Pilehvar, S.; Reinemann, C.; Bottari, F.; Vanderleyden, E.; Van Vlierberghe, S.; Blust, R.; Strehlitz, B.; De Wael, K. |
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Title |
A joint action of aptamers and gold nanoparticles chemically trapped on a glassy carbon support for the electrochemical sensing of ofloxacin |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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Volume |
240 |
Issue |
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Pages |
1024-1035 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
A joint action of ssDNA aptamers and electrochemistry is a key element in developing successful biosensing platforms, since aptamers are capable of binding various targets with high specificity, and electrochemistry is one of the most sensitive techniques for on-site detections. A continuous search for improved immobilization and sensing strategies of aptamers on transducer surfaces resulted in the strategy presented in this article. The strategy is based on the covalent attachment of gold nanoparticles on the surface of glassy carbon electrodes through sulfhydryl-terminated monolayer, acting as a glue to connect AuNPs on the electrode. The covalently attached gold nanoparticles modified glassy carbon electrodes have been applied for the efficient immobilization of thiolated ssDNA probes, with a surface coverage of about 8.54 × 1013 molecules cm−2 which was 7-fold higher than that on the electrochemically deposited gold nanoparticles. Consequently, improved sensitivity, good reproducibility and stability are achieved for electrochemical aptasensor. Combined with the high affinity and specificity of an aptamer, a simple, novel, rapid, sensitive and label-free electrochemical aptasensor was successfully fabricated for ofloxacin (OFL) detection. The linear dynamic range of the sensor varies between 5 × 10−8 to 2 × 10−5 M OFL with a detection limit of 1 × 10−9 M OFL. A potential application in environmental monitoring was demonstrated by using this sensing strategy for the determination of OFL in (experimentally spiked) real samples such as tap water and effluent of sewage treatment plant. The proposed nanoaptasensor combines the advantages of the covalent attachment of neatly arranged AuNPs (enlarged active surface area and strengthened electrochemical signal) and the elimination of labels for the amplified detection of OFL, with the covalent attachment of highly specific aptamers to the surface of the modified electrode. |
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Wos |
000390622300123 |
Publication Date |
2016-09-16 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0925-4005 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.401 |
Times cited |
21 |
Open Access |
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Notes |
; This work was financially supported by the University of Antwerp (BOF), The Research Foundation – Flanders (FWO) and The Hercules Foundation. S. P. is thankful to UA for DOCPRO financial support. C.R. and B.S. acknowledge funding by the Federal Ministry of Education and Research (BMBF) under contract no. 03X0094B. ; |
Approved |
Most recent IF: 5.401 |
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Call Number |
UA @ admin @ c:irua:135410 |
Serial |
5682 |
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