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Author | Rodríguez-Fernández, D.; Altantzis, T.; Heidari, H.; Bals, S.; Liz-Marzan, L.M. | ||||
Title | A protecting group approach toward synthesis of Au-silica Janus nanostars | Type | A1 Journal article | ||
Year | 2014 | Publication | Chemical communications | Abbreviated Journal | Chem Commun |
Volume | 50 | Issue | 1 | Pages | 79-81 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The concept of protecting groups, widely used in organic chemistry, has been applied for the synthesis of Au-silica Janus stars, in which gold branches protrude from one half of Au-silica Janus spheres. This configuration opens up new possibilities to apply the plasmonic properties of gold nanostars, as well as a variety of chemical functionalizations on the silica component. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000327606000017 | Publication Date | 2013-10-22 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1359-7345;1364-548X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.319 | Times cited | 26 | Open Access | OpenAccess |
Notes | 262348 Esmi; 335078 Colouratom; 267867 Plasmaquo; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); | Approved ![]() |
Most recent IF: 6.319; 2014 IF: 6.834 | ||
Call Number | UA @ lucian @ c:irua:112774 | Serial | 2732 | ||
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Author | Yalcin, A.O.; Goris, B.; van Dijk-Moes, R.J.A.; Fan, Z.; Erdamar, A.K.; Tichelaar, F.D.; Vlugt, T.J.H.; Van Tendeloo, G.; Bals, S.; Vanmaekelbergh, D.; Zandbergen, H.W.; van Huis, M.A.; | ||||
Title | Heat-induced transformation of CdSe-CdS-ZnS coremultishell quantum dots by Zn diffusion into inner layers | Type | A1 Journal article | ||
Year | 2015 | Publication | Chemical communications | Abbreviated Journal | Chem Commun |
Volume | 51 | Issue | 51 | Pages | 3320-3323 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | In this work, we investigate the thermal evolution of CdSeCdSZnS coremultishell quantum dots (QDs) in situ using transmission electron microscopy (TEM). Starting at a temperature of approximately 250 °C, Zn diffusion into inner layers takes place together with simultaneous evaporation of particularly Cd and S. As a result of this transformation, CdxZn1−xSeCdyZn1−yS coreshell QDs are obtained. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000349325000004 | Publication Date | 2014-11-21 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1359-7345;1364-548X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.319 | Times cited | 21 | Open Access | OpenAccess |
Notes | 262348 Esmi; Fwo; 246791 Countatoms; 335078 Colouratom; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); | Approved ![]() |
Most recent IF: 6.319; 2015 IF: 6.834 | ||
Call Number | c:irua:132582 | Serial | 1412 | ||
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Author | Aghaei, M.; Lindner, H.; Bogaerts, A. | ||||
Title | Ion Clouds in the Inductively Coupled Plasma Torch: A Closer Look through Computations | Type | A1 Journal article | ||
Year | 2016 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 88 | Issue | 88 | Pages | 8005-8018 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
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. | ||||
Address | Research Group PLASMANT, Chemistry Department, University of Antwerp , Universiteitsplein 1, 2610 Antwerp, Belgium | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000381654800020 | Publication Date | 2016-07-26 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 9 | Open Access | |
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 | ||
Call Number | PLASMANT @ plasmant @ c:irua:135644 | Serial | 4293 | ||
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Author | Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K. | ||||
Title | Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings | Type | A1 Journal article | ||
Year | 2017 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 89 | Issue | 89 | Pages | 3326-3334 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
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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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Washington, D.C. | Editor | ||
Language | Wos | 000397478300015 | Publication Date | 2017-02-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 7 | Open Access | OpenAccess |
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 | ||
Call Number | UA @ lucian @ c:irua:140886 | Serial | 4451 | ||
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Author | Fuchs, J.; Aghaei, M.; Schachel, T.D.; Sperling, M.; Bogaerts, A.; Karst, U. | ||||
Title | Impact of the Particle Diameter on Ion Cloud Formation from Gold Nanoparticles in ICPMS | Type | A1 Journal article | ||
Year | 2018 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 17 | Pages | 10271-10278 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | The unique capabilities of microsecond dwell time (DT) single-particle inductively coupled plasma mass spectrometry (spICPMS) were utilized to characterize the cloud of ions generated from the introduction of suspensions of gold nanoparticles (AuNPs) into the plasma. A set of narrowly distributed particles with diameters ranging from 15.4 to 100.1 nm was synthesized and characterized according to established protocols. Statistically significant numbers of the short transient spICPMS events were evaluated by using 50 μs DT for their summed intensity, maximum intensity, and duration, of which all three were found to depend on the particle diameter. The summed intensity increases from 10 to 1661 counts and the maximum intensity from 6 to 309 counts for AuNPs with diameters from 15.4 to 83.2 nm. The event duration rises from 322 to 1007 μs upon increasing AuNP diameter. These numbers represent a comprehensive set of key data points of the ion clouds generated in ICPMS from AuNPs. The extension of event duration is of high interest to appoint the maximum possible particle number concentration at which separation of consecutive events in spICPMS can still be achieved. Moreover, the combined evaluation of all above-mentioned ion cloud characteristics can explain the regularly observed prolonged single-particle events. The transport and ionization behavior of AuNPs in the ICP was also computationally modeled to gain insight into the size-dependent signal generation. The simulated data reveals that the plasma temperature, and therefore the point of ionization of the particles, is the same for all diameters. However, the maximum number density of Au+, as well as the extent of the ion cloud, depends on the particle diameter, in agreement with the experimental data, and it provides an adequate explanation for the observed ion cloud characteristics. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000444060600028 | Publication Date | 2018-09-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 5 | Open Access | OpenAccess |
Notes | We thank Dr. Harald Rösner from the Institute of Materials Physics of the University of Münster for the TEM imaging. | Approved ![]() |
Most recent IF: 6.32 | ||
Call Number | PLASMANT @ plasmant @c:irua:153651 | Serial | 5057 | ||
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Author | Gorbanev, Y.; Privat-Maldonado, A.; Bogaerts, A. | ||||
Title | Analysis of Short-Lived Reactive Species in Plasma–Air–Water Systems: The Dos and the Do Nots | Type | A1 Journal Article | ||
Year | 2018 | Publication | Analytical Chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 22 | Pages | 13151-13158 |
Keywords | A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
Abstract | This Feature addresses the analysis of the reactive species generated by nonthermal atmospheric pressure plasmas, which are widely employed in industrial and biomedical research, as well as first clinical applications. We summarize the progress in detection of plasma-generated short-lived reactive oxygen and nitrogen species in aqueous solutions, discuss the potential and limitations of various analytical methods in plasma−liquid systems, and provide an outlook on the possible future research goals in development of short-lived reactive species analysis methods for a general nonspecialist audience. |
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000451246100002 | Publication Date | 2018-11-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 17 | Open Access | Not_Open_Access |
Notes | European Commission, 743151 ; This work was supported by the European Marie Sklodowska- Curie Individual Fellowship within Horizon2020 (“LTPAM”, Grant No. 743151). | Approved ![]() |
Most recent IF: 6.32 | ||
Call Number | PLASMANT @ plasmant @c:irua:156301 | Serial | 5152 | ||
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Author | Sleegers, N.; van Nuijs, A.L.N.; van den Berg, M.; De Wael, K. | ||||
Title | Cephalosporin antibiotics : electrochemical fingerprints and core structure reactions investigated by LC-MSMS | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 3 | Pages | 2035-2041 |
Keywords | A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre | ||||
Abstract | Electrochemistry and exploiting electrochemical fingerprints is a potent approach to address newly emerging surveillance needs, for instance for antibiotics. However, a comprehensive insight in the electrochemical oxidation behaviour and mechanism is re-quired for this sensing strategy. To address the lack in knowledge of the voltammetric behaviour of the cephalosporins antibiotics, a selection of cephalosporin antibiotics and two main intermediates were subjected to an electrochemical study of their redox behaviour by means of pulsed voltammetric techniques and small-scale electrolysis combined with HPLC-MS/MS analyses. Sur-prisingly, the detected oxidation products did not fit the earlier suggested oxidation of the sulfur group to the corresponding sul-foxide. The influence of different side chains, both at the three and the seven position of the β-lactam core structure on the elec-trochemical fingerprint were investigated. Additional oxidation signals at lower potentials were elucidated and linked to different side chains. These signals were further exploited to allow simultaneous detection of different cephalosporins in one voltammetric sweep. These fundamental insights can become the building blocks for an new on-site screening method. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000458220300055 | Publication Date | 2019-01-03 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 6 | Open Access | |
Notes | ; The authors acknowledge financial support from the Fund for Scientific Research (FWO) Flanders, Grant 1S 37658 17N. ; | Approved ![]() |
Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:156046 | Serial | 5497 | ||
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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. | ||||
Title | Combined computed nanotomography and nanoscopic x-ray fluorescence imaging of cobalt nanoparticles in caenorhabditis elegans | Type | A1 Journal article | ||
Year | 2017 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 89 | Issue | 21 | Pages | 11435-11442 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
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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Publisher | Place of Publication | Editor | |||
Language | Wos | 000414887000041 | Publication Date | 2017-10-10 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 13 | Open Access | |
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 | ||
Call Number | UA @ admin @ c:irua:147383 | Serial | 5520 | ||
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Author | Florea, A.; Schram, J.; De Jong, M.; Eliaerts, J.; Van Durme, F.; Kaur, B.; Samyn, N.; De Wael, K. | ||||
Title | Electrochemical strategies for adulterated heroin samples | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 12 | Pages | 7920-7928 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | Electrochemical strategies to selectively detect heroin in street samples without the use of complicated electrode modifications were developed for the first time. For this purpose, heroin, mixing agents (adulterants, cutting agent, and impurities), and their binary mixtures were subjected to square wave voltammetry measurements at bare graphite electrodes at pH 7.0 and pH 12.0, in order to elucidate the unique electrochemical fingerprint of heroin and mixing agents as well as possible interferences or reciprocal influences. Adjusting the pH from pH 7.0 to pH 12.0 allowed a more accurate detection of heroin in the presence of most common mixing agents. Furthermore, the benefit of introducing a preconditioning step prior to running square wave voltammetry on the electrochemical fingerprint enrichment was explored. Mixtures of heroin with other drugs (cocaine, 3,4-methylenedioxymethamphetamine, and morphine) were also tested to explore the possibility of their discrimination and simultaneous detection. The feasibility of the proposed electrochemical strategies was tested on realistic heroin street samples from forensic cases, showing promising results for fast, on-site detection tools of drugs of abuse. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000472682000056 | Publication Date | 2019-05-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 2 | Open Access | |
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. The authors also acknowledge IOF (UAntwerp) and Belspo for financial support. ; | Approved ![]() |
Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:160061 | Serial | 5596 | ||
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Author | Morales-Yanez, F.; Trashin, S.; Hermy, M.; Sariego, I.; Polman, K.; Muyldermans, S.; De Wael, K. | ||||
Title | Fast one-step ultrasensitive detection of toxocara canis antigens by a nanobody-based electrochemical magnetosensor | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 18 | Pages | 11582-11588 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | Human toxocariasis (HT) is a cosmopolitan zoonotic disease caused by the migration of the larval stage of the roundworm Toxocara canis. Current HT diagnostic methods do not discriminate between active and past infections. Here, we present a method to quantify Toxocara excretory/secretory antigen, aiming to identify active cases of HT. High specificity is achieved by employing nanobodies (Nbs), single domain antigen binding fragments from camelid heavy chain-only antibodies. High sensitivity is obtained by the design of an electrochemical magnetosensor with an amperometric read-out. Reliable detection of TES antigen at 10 and 30 pg/mL level was demonstrated in phosphate buffered saline and serum, respectively. Moreover, the assay showed no cross-reactivity with other nematode antigens. To our knowledge, this is the most sensitive method to quantify the TES antigen so far. It also has great potential to develop point of care diagnostic systems in other conditions where high sensitivity and specificity are required. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000487156900016 | Publication Date | 2019-08-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 2 | Open Access | |
Notes | ; This project was funded by the Fonds Wetenschappelijk Onderzoek-Vlaanderen (FWO-Flanders, Project G.0189.13N) and BOF UAntwerp. The authors acknowledge Prof. Pierre Dorny (Institute of Tropical Medicine Antwerp) and Dr. Beatrice Nickel (Swiss Institute of Tropical Medicine) for providing the antigens needed for the cross-reactivity experiments. ; | Approved ![]() |
Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:163784 | Serial | 5621 | ||
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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. | ||||
Title | Levamisole : a common adulterant in cocaine street samples hindering electrochemical detection of cocaine | Type | A1 Journal article | ||
Year | 2018 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 8 | Pages | 5290-5297 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre | ||||
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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Publisher | Place of Publication | Editor | |||
Language | Wos | 000430512200049 | Publication Date | 2018-02-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 8 | Open Access | |
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 | ||
Call Number | UA @ admin @ c:irua:149528 | Serial | 5693 | ||
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Author | Vanmeert, F.; de Nolf, W.; De Meyer, S.; Dik, J.; Janssens, K. | ||||
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 | ||
Year | 2018 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 11 | Pages | 6436-6444 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
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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Publisher | Place of Publication | Editor | |||
Language | Wos | 000434893200019 | Publication Date | 2018-04-06 | |
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Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 11 | Open Access | |
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 | ||
Call Number | UA @ admin @ c:irua:151993 | Serial | 5701 | ||
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Author | Vanmeert, F.; de Nolf, W.; Dik, J.; Janssens, K. | ||||
Title | Macroscopic X-ray powder diffraction scanning : possibilities for quantitative and depth-selective parchment analysis | Type | A1 Journal article | ||
Year | 2018 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 11 | Pages | 6445-6452 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | At or below the surface of painted works of art, valuable information is present that provides insights into an objects past, such as the artists technique and the creative process that was followed or its conservation history but also on its current state of preservation. Various noninvasive techniques have been developed over the past 2 decades that can probe this information either locally (via point analysis) or on a macroscopic scale (e.g., full-field imaging and raster scanning). Recently macroscopic X-ray powder diffraction (MA-XRPD) mapping using laboratory X-ray sources was developed. This method can visualize highly specific chemical distributions at the macroscale (dm(2)). In this work we demonstrate the synergy between the quantitative aspects of powder diffraction and the noninvasive scanning capability of MA-XRPD highlighting the potential of the method to reveal new types of information. Quantitative data derived from a 15th/16th century illuminated sheet of parchment revealed three lead white pigments with different hydrocerussite-cerussite compositions in specific pictorial elements, while quantification analysis of impurities in the blue azurite pigment revealed two distinct azurite types: one rich in barite and one in quartz. Furthermore, on the same artifact, the depth-selective possibilities of the method that stem from an exploitation of the shift of the measured diffraction peaks with respect to reference data are highlighted. The influence of different experimental parameters on the depth-selective analysis results is briefly discussed. Promising stratigraphic information could be obtained, even though the analysis is hampered by not completely understood variations in the unit cell dimensions of the crystalline pigment phases. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000434893200020 | Publication Date | 2018-04-06 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 6 | Open Access | |
Notes | ; The authors thank Incoatec GmbH for giving us the opportunity to test the I mu S Cu X-ray source. 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 | ||
Call Number | UA @ admin @ c:irua:151994 | Serial | 5702 | ||
Permanent link to this record | |||||
Author | Neven, L.; Thiruvottriyur Shanmugam, S.; Rahemi, V.; Trashin, S.; Sleegers, N.; Carrion, E.N.; Gorun, S.M.; De Wael, K. | ||||
Title | Optimized photoelectrochemical detection of essential drugs bearing phenolic groups | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 15 | Pages | 9962-9969 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
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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Publisher | Place of Publication | Editor | |||
Language | Wos | 000480499200086 | Publication Date | 2019-06-25 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 2 | Open Access | |
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 | ||
Call Number | UA @ admin @ c:irua:161831 | Serial | 5763 | ||
Permanent link to this record | |||||
Author | Alvarez-Martin, A.; Cleland, T.P.; Kavich, G.M.; Janssens, K.; Newsome, G.A. | ||||
Title | Rapid evaluation of the debromination mechanism of eosin in oil paint by direct analysis in real time and direct infusion-electrospray ionization mass spectrometry | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 16 | Pages | 10856-10863 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | Eosin is a synthetic organic colorant prone to fading under the influence of light. On the basis of the growing interest in the understanding of the discoloration mechanism of eosin-based lakes, this study compares the ability of two ultrafast and ultrasensitive mass spectrometry techniques to detect eosin derivatives in complex matrices, such as oil media without the use of conventional separation columns or additional sample preparation protocols. Direct analysis in real time mass spectrometry (DART-MS) and direct infusion electrospray ionization mass spectrometry (DI-ESI-MS) were used to characterize the degradation pathway of eosin in oil media. The analysis protocols developed in this study are applied to discern the degradation mechanism of the lake pigment eosin (comprising the molecule per se complexed to an inorganic substrate) dispersed in linseed oil to create an oil paint. The analysis of oil paints by high resolution MS without an extraction methodology that modifies the system chemistry allowed us to identify the degradation forms without causing any additional fragmentation. Both techniques revealed the primary photodegradation pathway of eosin in linseed oil, and DI-ESI-MS provided additional information on the native conformation of the lake. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000482545300069 | Publication Date | 2019-07-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 3 | Open Access | |
Notes | ; The authors would like to acknowledge the SolarPaint project (GOA program, Antwerp University Research Council) and Smithsonian Institution for financial support. ; | Approved ![]() |
Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:162879 | Serial | 5800 | ||
Permanent link to this record | |||||
Author | De Jong, M.; Florea, A.; Eliaerts, J.; Van Durme, F.; Samyn, N.; De Wael, K. | ||||
Title | Tackling poor specificity of cocaine color tests by electrochemical strategies | Type | A1 Journal article | ||
Year | 2018 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 90 | Issue | 11 | Pages | 6811-6819 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | This paper presents electrochemical strategies for the fast screening of cocaine and most common cutting agents found in seized drug samples. First, a study on the performance of Scott color tests on cocaine and a wide range of cutting agents is described. The cutting agents causing false positive or false negative results when in mixture with cocaine are identified. To overcome the lack of specificity of color tests, we further propose a fast screening strategy by means of square wave voltammetry on disposable graphite screen printed electrodes, which reveals the unique fingerprint of cocaine and cutting agents. By employing a forward and backward scan and by a dual pH strategy, we enrich the electrochemical fingerprint and enable the simultaneous detection of cocaine and cutting agents. The effectiveness of the developed strategies was tested for the detection of cocaine in seized cocaine samples and compared with the color tests. Moreover, we prove the usefulness of square wave voltammetry for predicting possible interfering agents in color tests, based on the reduction peak of cobalt thiocyanate. The developed electrochemical strategies allow for a quick screening of seized cocaine samples resulting in a selective identification of drugs and cutting agents. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000434893200066 | Publication Date | 2018-05-09 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 7 | Open Access | |
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 Grants BR/314 /PI/APTADRU and IOF-SBO. ; | Approved ![]() |
Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:151316 | Serial | 5867 | ||
Permanent link to this record | |||||
Author | Vanmeert, F.; De Keyser, N.; van Loon, A.; Klaassen, L.; Noble, P.; Janssens, K. | ||||
Title | Transmission and reflection mode macroscopic x-ray powder diffraction imaging for the noninvasive visualization of paint degradation in still life paintings by Jan Davidsz. de Heem | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 11 | Pages | 7153-7161 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | The use of noninvasive chemical imaging techniques is becoming more widespread for the study of cultural heritage artifacts. Recently a mobile instrument for macroscopic X-ray powder diffraction (MA-XRPD) scanning was developed, which is capable of visualizing the distribution of crystalline (pigment) phases in quasi-flat-painted artifacts. In this study, MA-XRPD is used in both transmission and reflection mode for the analysis of three 17th century still life paintings, two paintings by Jan Davidsz. de Heem (1606-1684) and one copy painting after De Heem by an unknown artist. MA-XRPD allowed to reveal and map the presence of in situ-formed alteration products. In the works examined, two rare lead arsenate minerals, schultenite (PbHAsO4) and mimetite (Pb-5(AsO4)(3)Cl), were encountered, both at and below the paint surface; they are considered to be degradation products of the pigments realgar (alpha-As4S4) and orpiment (As2S3). In transmission mode, the depletion of lead white, present in the (second) ground layer, could be seen, illustrating the intrusive nature of this degradation process. In reflection mode, several sulfate salts, palmierite (K2Pb(SO4)(2)), syngenite (K2Ca(SO4)(2)center dot H2O), and gypsum (CaSO4 center dot 2H(2)O), could be detected, in particular, at the (top) surface of the copy painting. Estimates for the information depth and sensitivity of both transmission and reflection mode MA-XRPD for various pigments have been made. The possibility of MA-XRPD to allow for noninvasive identification and visualization of alteration products is considered a significant advantage and unique feature of this method. MA-XRPD can thus provide highly relevant information for assessing the conservation state of artworks and could guide possible future restoration treatments. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000470793800031 | Publication Date | 2019-05-10 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 5 | Open Access | |
Notes | ; The authors acknowledge financial support from BELSPO (Brussels) S2-ART and METOX projects, the NWO (The Hague) Science4Arts “ReVisRembrandt” project, and the GOA Project Solarpaint (University of Antwerp Research Council). The authors thank the Rijksmuseum, the Royal Museum of Fine Arts Antwerp, and their staff for the collaborations. ; | Approved ![]() |
Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:160245 | Serial | 5882 | ||
Permanent link to this record | |||||
Author | De Jong, M.; Sleegers, N.; Florea, A.; Van Loon, J.; van Nuijs, A.L.N.; Samyn, N.; De Wael, K. | ||||
Title | Unraveling the mechanisms behind the complete suppression of cocaine electrochemical signals by chlorpromazine, promethazine, procaine, and dextromethorphan | Type | A1 Journal article | ||
Year | 2019 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 91 | Issue | 24 | Pages | 15453-15460 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre; Product development | ||||
Abstract | The present work investigates the challenges accompanied by the electrochemical cocaine detection in physiological conditions (pH 7) in the presence of chlorpromazine, promethazine, procaine, and dextromethorphan, frequently used cutting agents in cocaine street samples. The problem translates into the absence of the cocaine oxidation signal (signal suppression) when in a mixture with one of these compounds, leading to false negative results. Although a solution to this problem was provided through earlier experiments of our group, the mechanisms behind the suppression are now fundamentally investigated via electrochemical and liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) strategies. The latter was used to confirm the passivation of the electrodes due to their interaction with promethazine and chlorpromazine. Electron transfer mechanisms were further identified via linear sweep voltammetry. Next, adsorption experiments were performed on the graphite screen printed electrodes both with and without potential assistance in order to confirm if the suppression of the cocaine signals is due to passivation induced by the cutting agents or their oxidized products. The proposed strategies allowed us to identify the mechanisms of cocaine suppression for each cutting agent mentioned. Suppression due to procaine and dextromethorphan is caused by fouling of the electrode surface by their oxidized forms, while for chlorpromazine and promethazine the suppression of the cocaine signal is related to the strong adsorption of these (nonoxidized) cutting agents onto the graphite electrode surface. These findings provide fundamental insights in possible suppression and other interfering mechanisms using electrochemistry in general not only in the drug detection sector. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000503910600018 | Publication Date | 2019-11-14 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | Open Access | ||
Notes | ; The authors acknowledge financial support from IOF-SBO/POC (UAntwerp) and the Fund for Scientific Research (FWO) Flanders, Grant 1S 37658 17N. ; | Approved ![]() |
Most recent IF: 6.32 | ||
Call Number | UA @ admin @ c:irua:165727 | Serial | 5887 | ||
Permanent link to this record | |||||
Author | Ayalew, E.; Janssens, K.; De Wael, K. | ||||
Title | Unraveling the reactivity of minium towards bicarbonate and the role of lead oxides therein | Type | A1 Journal article | ||
Year | 2016 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 88 | Issue | 3 | Pages | 1564-1569 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
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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Publisher | Place of Publication | Editor | |||
Language | Wos | 000369471100014 | Publication Date | 2015-12-31 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 9 | Open Access | |
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 | ||
Call Number | UA @ admin @ c:irua:129963 | Serial | 5888 | ||
Permanent link to this record | |||||
Author | Aghaei, M.; Bogaerts, A. | ||||
Title | Flowing Atmospheric Pressure Afterglow for Ambient Ionization: Reaction Pathways Revealed by Modeling | Type | A1 Journal article | ||
Year | 2021 | Publication | Analytical Chemistry | Abbreviated Journal | Anal Chem |
Volume | 93 | Issue | 17 | Pages | 6620-6628 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
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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Publisher | Place of Publication | Editor | |||
Language | Wos | 000648505900008 | Publication Date | 2021-05-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | Open Access | OpenAccess | |
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 | ||
Call Number | PLASMANT @ plasmant @c:irua:178126 | Serial | 6762 | ||
Permanent link to this record | |||||
Author | Sleegers, N.; van Nuijs, A.L.N.; van den Berg, M.; De Wael, K. | ||||
Title | Electrochemistry of intact versus degraded cephalosporin antibiotics facilitated by LC–MS analysis | Type | A1 Journal article | ||
Year | 2021 | Publication | Analytical Chemistry | Abbreviated Journal | Anal Chem |
Volume | 93 | Issue | 4 | Pages | 2394-2402 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre | ||||
Abstract | The electrochemical detection of cephalosporins is a promising approach for the monitoring of cephalosporin levels in process waters. However, this class of antibiotics, like penicillins, is composed of chemically active molecules and susceptible to hydrolysis and aminolysis of the four membered β-lactam ring present. In order to develop a smart monitoring strategy for cephalosporins, the influence of degradation (hydrolysis and aminolysis) on the electrochemical fingerprint has to be taken into account. Therefore, an investigation was carried out to understand the changes of the voltammetric fingerprints upon acidic and alkaline degradation. Changes in fingerprints were correlated to the degradation pathways through the combination of square wave voltammetry and liquid chromatography quadrupole time-of-flight analysis. The characteristic electrochemical signals of the β-lactam ring disappeared upon hydrolysis. Additional oxidation signals that appeared after degradation were elucidated and linked to different degradation products, and therefore, enrich the voltammetric fingerprints with information of the state of the cephalosporins. The applicability of the electrochemical monitoring system was explored by the analysis of the intact and degraded industrial process waters containing the key intermediate 7-aminodeacetoxycephalosporanic acid (7-ADCA). Clearly, the intact process samples exhibited the expected core signals of 7-ADCA and could be quantified, while the degraded samples only showed the newly formed degradation products. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000618089100063 | Publication Date | 2021-01-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | Open Access | Not_Open_Access | |
Notes | Approved ![]() |
Most recent IF: 6.32 | |||
Call Number | UA @ admin @ c:irua:176206 | Serial | 7864 | ||
Permanent link to this record | |||||
Author | Alvarez-Martin, A.; Newsome, G.A.; Janssens, K. | ||||
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 |
Volume | 93 | Issue | 44 | Pages | 14851-14858 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp X-ray Imaging and Spectroscopy (AXIS) | ||||
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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Publisher | Place of Publication | Editor | |||
Language | Wos | 000718171600037 | Publication Date | 2021-10-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | Open Access | OpenAccess | |
Notes | Approved ![]() |
Most recent IF: 6.32 | |||
Call Number | UA @ admin @ c:irua:182347 | Serial | 8038 | ||
Permanent link to this record | |||||
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. | ||||
Title | Nanobody-based immunosensor detection enhanced by photocatalytic-electrochemical redox cycling | Type | A1 Journal article | ||
Year | 2021 | Publication | Analytical Chemistry | Abbreviated Journal | Anal Chem |
Volume | 93 | Issue | 40 | Pages | 13606-13614 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) | ||||
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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Publisher | Place of Publication | Editor | |||
Language | Wos | 000708550500025 | Publication Date | 2021-09-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | Open Access | OpenAccess | |
Notes | Approved ![]() |
Most recent IF: 6.32 | |||
Call Number | UA @ admin @ c:irua:181795 | Serial | 8290 | ||
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Author | Verlinden, G.; Janssens, G.; Gijbels, R.; van Espen, P.; Geuens, I. | ||||
Title | Three-dimensional chemical characterization of complex silver halide microcrystals by scanning ion microprobe mass analysis | Type | A1 Journal article | ||
Year | 1997 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 69 | Issue | Pages | 3773-3779 | |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Chemometrics (Mitac 3) | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Washington, D.C. | Editor | ||
Language | Wos | A1997XV71200019 | Publication Date | 2002-07-26 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700;1520-6882; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 6 | Open Access | |
Notes | Approved ![]() |
Most recent IF: 6.32; 1997 IF: 4.743 | |||
Call Number | UA @ lucian @ c:irua:16959 | Serial | 3647 | ||
Permanent link to this record | |||||
Author | Gregory, C.L.; Nullens, H.A.; Gijbels, R.H.; van Espen, P.J.; Geuens, I.; de Keyzer, R. | ||||
Title | Automated particle analysis of populations of silver halide microcrystals by electron probe microanalysis under cryogenic conditions | Type | A1 Journal article | ||
Year | 1998 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 70 | Issue | Pages | 2551-2559 | |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Chemometrics (Mitac 3) | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Washington, D.C. | Editor | ||
Language | Wos | 000074584700047 | Publication Date | 2002-07-26 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700;1520-6882; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 12 | Open Access | |
Notes | Approved ![]() |
Most recent IF: 6.32; 1998 IF: 4.580 | |||
Call Number | UA @ lucian @ c:irua:21308 | Serial | 210 | ||
Permanent link to this record | |||||
Author | Poels, K.; van Vaeck, L.; Gijbels, R. | ||||
Title | Microprobe speciation analysis of inorganic solids by Fourier transform laser mass spectrometry | Type | A1 Journal article | ||
Year | 1998 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 70 | Issue | Pages | 504-512 | |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Washington, D.C. | Editor | ||
Language | Wos | 000071810400012 | Publication Date | 2002-07-26 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700;1520-6882; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 32 | Open Access | |
Notes | Approved ![]() |
Most recent IF: 6.32; 1998 IF: 4.580 | |||
Call Number | UA @ lucian @ c:irua:19338 | Serial | 2026 | ||
Permanent link to this record | |||||
Author | Bings, N.H.; Bogaerts, A.; Broekaert, J.A.C. | ||||
Title | Atomic spectroscopy | Type | A1 Journal article | ||
Year | 2002 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 74 | Issue | 12 | Pages | 2691-2712 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Washington, D.C. | Editor | ||
Language | Wos | 000176253700006 | Publication Date | 2002-07-26 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700;1520-6882; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 18 | Open Access | |
Notes | Approved ![]() |
Most recent IF: 6.32; 2002 IF: 5.094 | |||
Call Number | UA @ lucian @ c:irua:40192 | Serial | 194 | ||
Permanent link to this record | |||||
Author | Kempenaers, L.; Janssens, K.; Vincze, L.; Vekemans, B.; Somogyi, A.; Drakopoulos, M.; Simionovici, A.S.; Adams, F. | ||||
Title | A Monte Carlo model for studying the microheterogeneity of trace elements in reference materials by means of synchrotron microscopic X-ray fluorescence | Type | A1 Journal article | ||
Year | 2002 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 74 | Issue | 19 | Pages | 5017-5026 |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000178418100031 | Publication Date | 2002-09-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 21 | Open Access | |
Notes | Approved ![]() |
Most recent IF: 6.32; 2002 IF: 5.094 | |||
Call Number | UA @ admin @ c:irua:39871 | Serial | 5734 | ||
Permanent link to this record | |||||
Author | Vincze, L.; Somogyi, A.; Osán, J.; Vekemans, B.; Török, S.; Janssens, K.; Adams, F. | ||||
Title | Quantitative trace element analysis of individual fly ash particles by means of X-ray microfluorescence | Type | A1 Journal article | ||
Year | 2002 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 74 | Issue | Pages | 1128-1135 | |
Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000174187900032 | Publication Date | 2006-06-10 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 44 | Open Access | |
Notes | Approved ![]() |
Most recent IF: 6.32; 2002 IF: 5.094 | |||
Call Number | UA @ admin @ c:irua:38377 | Serial | 5796 | ||
Permanent link to this record | |||||
Author | Bings, N.H.; Bogaerts, A.; Broekaert, J.A.C. | ||||
Title | Atomic spectroscopy | Type | A1 Journal article | ||
Year | 2004 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
Volume | 76 | Issue | 12 | Pages | 3313-3336 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Washington, D.C. | Editor | ||
Language | Wos | 000222011100006 | Publication Date | 2004-06-14 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0003-2700;1520-6882; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.32 | Times cited | 32 | Open Access | |
Notes | Approved ![]() |
Most recent IF: 6.32; 2004 IF: 5.450 | |||
Call Number | UA @ lucian @ c:irua:46258 | Serial | 193 | ||
Permanent link to this record |