|   | 
Details
   web
Records
Author Smets, B.; Boschker, H.T.S.; Wetherington, M.T.; Lelong, G.; Hidalgo-Martinez, S.; Polerecky, L.; Nuyts, G.; De Wael, K.; Meysman, F.J.R.
Title Multi-wavelength Raman microscopy of nickel-based electron transport in cable bacteria Type A1 Journal article
Year 2024 Publication Frontiers in microbiology Abbreviated Journal
Volume 15 Issue Pages 1208033-16
Keywords A1 Journal article
Abstract Cable bacteria embed a network of conductive protein fibers in their cell envelope that efficiently guides electron transport over distances spanning up to several centimeters. This form of long-distance electron transport is unique in biology and is mediated by a metalloprotein with a sulfur-coordinated nickel (Ni) cofactor. However, the molecular structure of this cofactor remains presently unknown. Here, we applied multi-wavelength Raman microscopy to identify cell compounds linked to the unique cable bacterium physiology, combined with stable isotope labeling, and orientation-dependent and ultralow-frequency Raman microscopy to gain insight into the structure and organization of this novel Ni-cofactor. Raman spectra of native cable bacterium filaments reveal vibrational modes originating from cytochromes, polyphosphate granules, proteins, as well as the Ni-cofactor. After selective extraction of the conductive fiber network from the cell envelope, the Raman spectrum becomes simpler, and primarily retains vibrational modes associated with the Ni-cofactor. These Ni-cofactor modes exhibit intense Raman scattering as well as a strong orientation-dependent response. The signal intensity is particularly elevated when the polarization of incident laser light is parallel to the direction of the conductive fibers. This orientation dependence allows to selectively identify the modes that are associated with the Ni-cofactor. We identified 13 such modes, some of which display strong Raman signals across the entire range of applied wavelengths (405–1,064 nm). Assignment of vibrational modes, supported by stable isotope labeling, suggest that the structure of the Ni-cofactor shares a resemblance with that of nickel bis(1,2-dithiolene) complexes. Overall, our results indicate that cable bacteria have evolved a unique cofactor structure that does not resemble any of the known Ni-cofactors in biology.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001189511900001 Publication Date 2024-03-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1664-302x ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes (up) Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:205115 Serial 9214
Permanent link to this record
 

 
Author Pankratov, D.; Hidalgo Martinez, S.; Karman, C.; Gerzhik, A.; Gomila, G.; Trashin, S.; Boschker, H.T.S.; Geelhoed, J.S.; Mayer, D.; De Wael, K.; Meysman, F.J.R.
Title The organo-metal-like nature of long-range conduction in cable bacteria Type A1 Journal article
Year 2024 Publication Bioelectrochemistry: an international journal devoted to electrochemical aspects of biology and biological aspects of electrochemistry Abbreviated Journal
Volume 157 Issue Pages 108675-10
Keywords A1 Journal article
Abstract Cable bacteria are filamentous, multicellular microorganisms that display an exceptional form of biological electron transport across centimeter-scale distances. Currents are guided through a network of nickel-containing protein fibers within the cell envelope. Still, the mechanism of long-range conduction remains unresolved. Here, we characterize the conductance of the fiber network under dry and wet, physiologically relevant, conditions. Our data reveal that the fiber conductivity is high (median value: 27 S cm−1; range: 2 to 564 S cm−1), does not show any redox signature, has a low thermal activation energy (Ea = 69 ± 23 meV), and is not affected by humidity or the presence of ions. These features set the nickel-based conduction mechanism in cable bacteria apart from other known forms of biological electron transport. As such, conduction resembles that of an organic semi-metal with a high charge carrier density. Our observation that biochemistry can synthesize an organo-metal-like structure opens the way for novel bio-based electronic technologies.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2024-02-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1567-5394 ISBN Additional Links UA library record
Impact Factor 5 Times cited Open Access
Notes (up) Approved Most recent IF: 5; 2024 IF: 3.346
Call Number UA @ admin @ c:irua:205117 Serial 9215
Permanent link to this record
 

 
Author Thiruvottriyur Shanmugam, S.; Campos, R.; Trashin, S.; Daems, E.; Carneiro, D.; Fraga, A.; Ribeiro, R.; De Wael, K.
Title Singlet oxygen-based photoelectrochemical detection of miRNAs in prostate cancer patients’ plasma : a novel diagnostic tool for liquid biopsy Type A1 Journal article
Year 2024 Publication Bioelectrochemistry: an international journal devoted to electrochemical aspects of biology and biological aspects of electrochemistry Abbreviated Journal
Volume 158 Issue Pages 108698-108699
Keywords A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Abstract Dysregulation of miRNA expression occurs in many cancers, making miRNAs useful in cancer diagnosis and therapeutic guidance. In a clinical context using methods such as polymerase chain reaction (PCR), the limited amount of miRNAs in circulation often limits their quantification. Here, we present a PCR-free and sensitive singlet oxygen (1O2)-based strategy for the detection and quantification of miRNAs in untreated human plasma from patients diagnosed with prostate cancer. A target miRNA is specifically captured by functionalised magnetic beads and a detection oligonucleotide probe in a sandwich-like format. The formed complex is concentrated at the sensor surface via magnetic beads, providing an interface for the photoinduced redox signal amplification. The detection oligonucleotide probe bears a molecular photosensitiser, which produces 1O2 upon illumination, oxidising a redox reporter and creating a redox cycling loop, allowing quantification of pM level miRNA in diluted human plasma within minutes after hybridisation and without target amplification.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2024-04-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1567-5394 ISBN Additional Links UA library record
Impact Factor 5 Times cited Open Access
Notes (up) Approved Most recent IF: 5; 2024 IF: 3.346
Call Number UA @ admin @ c:irua:205281 Serial 9229
Permanent link to this record
 

 
Author Elia, A.; De Wael, K.; Dowsett, M.; Adriaens, A.
Title Electrochemical deposition of a copper carboxylate layer on copper as potential corrosion inhibitor Type A1 Journal article
Year 2011 Publication Journal of solid state electrochemistry Abbreviated Journal J Solid State Electr
Volume 16 Issue 1 Pages 143-148
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Carboxylic acids and sodium carboxylates are used to protect metals against aqueous and atmospheric corrosion. In this paper, we describe the application of a layer of copper carboxylate on the surface of a copper electrode by means of cyclic voltammetry technique and tests which measure the corresponding resistance to aqueous corrosion. Unlike the soaking process, which also forms a film on the surface, the use of cyclic voltammetry allows one to follow the deposition process of the copper carboxylates onto the electrode. The modified electrodes have been characterised with infrared spectroscopy. In addition, the corrosion resistance of the film has been investigated using polarisation resistance and Tafel plot measurements.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000298651700018 Publication Date 2011-01-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1432-8488 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.316 Times cited 8 Open Access
Notes (up) ; Authors would like to acknowledge the Research Foundation-Flanders (FWO) for funding assistance (A. Elia is a FWO aspirant) and V. Vermeersch and S. Van Vlierberghe (Ghent University, Polymer Chemistry and Biomaterials Research Group) for the FTIR-ATR measurements. ; Approved Most recent IF: 2.316; 2011 IF: 2.131
Call Number UA @ admin @ c:irua:89618 Serial 5588
Permanent link to this record
 

 
Author Eliaerts, J.; Meert, N.; Van Durme, F.; Samyn, N.; De Wael, K.; Dardenne, P.
Title Practical tool for sampling and fast analysis of large cocaine seizures Type A1 Journal article
Year 2018 Publication Drug testing and analysis Abbreviated Journal Drug Test Anal
Volume 10 Issue 6 Pages 1039-1042
Keywords A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Large quantities of illicit drugs are frequently seized by law enforcement. In such cases, a representative number of samples needs to be quickly examined prior to destruction. No procedure has yet been set up which rapidly provides information regarding the homogeneity of the samples, the presence of controlled substances and the degree of purity. This study establishes a protocol for fast analysis of cocaine and its most common cutting agent, levamisole, in large seizures. The protocol is based on a hypergeometric sampling approach combined with FTIR spectrometry and Support Vector Machines (SVM) algorithms as analysis methods. To demonstrate the practical use of this approach, five large cocaine seizures (consisting between 45 and 85 units) were analysed simultaneously with GC-MS, GC-FID and a portable FTIR spectrometer using Attenuated Total Reflectance (ATR) sampling combined with SVM models. According to the hypergeometric sampling plan of the Drugs Working Group ENFSI guidelines, the required number of subsamples ranged between 19 and 23. Considering the identification analyses, the SVM models detected cocaine and levamisole in all subsamples of cases 1 to 5 (100% correct classification), which was confirmed by GC-MS analysis. Considering the quantification analyses, the SVM models were able to estimate the cocaine and levamisole content in each subsample, compared to GC-FID data. The developed strategy is easy, cost effective and provides immediate information about both the presence and concentration of cocaine and levamisole. By using this new strategy, the number of confirmation analyses with laborious and expensive chromatographic techniques could be significantly reduced.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000435270300016 Publication Date 2018-02-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1942-7603; 1942-7611 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.469 Times cited 1 Open Access
Notes (up) ; Belgian Science Policy Office (BELSPO), Grant/Award Number: WE/49/N14-O14 ; Approved Most recent IF: 3.469
Call Number UA @ admin @ c:irua:148760 Serial 5781
Permanent link to this record
 

 
Author Pilehvar, S.; Jambrec, D.; Gebala, M.; Schuhmann, W.; De Wael, K.
Title Intercalation of proflavine in ssDNA aptamers : effect on binding of the specific target chloramphenicol Type A1 Journal article
Year 2015 Publication Electroanalysis Abbreviated Journal Electroanal
Volume 27 Issue 8 Pages 1836-1841
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The structural modification of ssDNA-based aptamers upon specific binding of its target molecule leads to changes of the charge-transfer resistance (Rct) of a negatively-charged free-diffusing redox probe. The aptamer adopts a structure due to self-hybridization which is stabilized using profalvine as intercalator. The pre-organized aptamer structure is used to detect chloramphenicol (CAP) requiring a substantial change of the aptamer structure indicated by a CAP concentration dependent increase in the Rct values. Pre-incubation of the aptamer-modified electrode with an intercalator allows for the modulation of the aptamer/target interaction and hence for a modulation of the CAP-dependent variation of the Rct values.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000359737500006 Publication Date 2015-06-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1040-0397 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.851 Times cited 5 Open Access
Notes (up) ; D. J., M. G., W. S. are grateful for financial support to the Deutsch-Israelische Projektkooperation (DIP) in the framework of the project “Nanoengineered optoelectronics with biomaterials and bioinspired assemblies” funded by the Deutsche Forschungsgemeinschaft. S. P. and K. D. W. are thankful to UA for DOCPRO financial support. ; Approved Most recent IF: 2.851; 2015 IF: 2.138
Call Number UA @ admin @ c:irua:126494 Serial 5666
Permanent link to this record
 

 
Author Trashin, S.; Rahemi, V.; Ramji, K.; Neven, L.; Gorun, S.M.; De Wael, K.
Title Singlet oxygen-based electrosensing by molecular photosensitizers Type A1 Journal article
Year 2017 Publication Nature communications Abbreviated Journal Nat Commun
Volume 8 Issue Pages 16108
Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Enzyme-based electrochemical biosensors are an inspiration for the development of (bio)analytical techniques. However, the instability and reproducibility of the reactivity of enzymes, combined with the need for chemical reagents for sensing remain challenges for the construction of useful devices. Here we present a sensing strategy inspired by the advantages of enzymes and photoelectrochemical sensing, namely the integration of aerobic photocatalysis and electrochemical analysis. The photosensitizer, a bioinspired perfluorinated Zn phthalocyanine, generates singlet-oxygen from air under visible light illumination and oxidizes analytes, yielding electrochemically-detectable products while resisting the oxidizing species it produces. Compared with enzymatic detection methods, the proposed strategy uses air instead of internally added reactive reagents, features intrinsic baseline correction via on/off light switching and shows C-F bonds-type enhanced stability. It also affords selectivity imparted by the catalytic process and nano-level detection, such as 20 nM amoxicillin in μl sample volumes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000405466200002 Publication Date 2017-07-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 26 Open Access
Notes (up) ; Evonik is thanked for providing samples of silicon and titanium oxides. Support from the National Science Foundation (SMG) for a portion of this work is gratefully acknowledged. FWO and UAntwerpen (BOF) are acknowledged for financial support. ; Approved Most recent IF: 12.124
Call Number UA @ admin @ c:irua:144538 Serial 5833
Permanent link to this record
 

 
Author Ayalew, E.; Gebre, Y.; De Wael, K.
Title A survey of occupational exposure to inhalable wood dust among workers in small- and medium-scale wood-processing enterprises in Ethiopia Type A1 Journal article
Year 2015 Publication The annals of occupational hygiene Abbreviated Journal Ann Occup Hyg
Volume 59 Issue 2 Pages 253-257
Keywords A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract A study of wood dust exposure in 20 small- and medium-scale wood-processing enterprises was performed in Ethiopia. Sampling was conducted daily from January to June, 2013 and a total of 360 samples from 113 workers were collected with Institute of Occupational Medicine (IOM) personal samplers. Eight-hour time-weighted average exposure to wood dust ranged from 0.24 to 23.3mg m−3 with a geometric mean (GM) of 6.82mg m−3 and a geometric standard deviation of 1.82. Although Ethiopia did not have any defined standard of Occupational Exposure Limit for wood dust exposure, 71% of the measurements exceeded the limit of 5mg m−3 set by the European Union (EU). Higher than the EU exposure limit was measured while workers perform sanding and sawing activities with a GM of 9.72 and 7.60mg m−3, respectively. In conclusion, wood workers in the small- and medium-scale enterprises are at a higher risk of developing different respiratory health problems with continuous exposure trends.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000352158700011 Publication Date 2014-10-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-4878 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.71 Times cited 4 Open Access
Notes (up) ; Eyasu Ayalew thanks the Addis Ababa University (Center for Environmental Sciences) for the personal grant for independent study. ; Approved Most recent IF: 1.71; 2015 IF: 2.101
Call Number UA @ admin @ c:irua:119739 Serial 5857
Permanent link to this record
 

 
Author Hamidi-Asl, E.; Dardenne, F.; Pilehvar, S.; Blust, R.; De Wael, K.
Title Unique properties of core shell Ag@Au nanoparticles for the aptasensing of bacterial cells Type A1 Journal article
Year 2016 Publication Chemosensors Abbreviated Journal
Volume 4 Issue 3 Pages 16
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract In this article, it is shown that the efficiency of an electrochemical aptasensing device is influenced by the use of different nanoparticles (NPs) such as gold nanoparticles (Au), silver nanoparticles (Ag), hollow gold nanospheres (HGN), hollow silver nanospheres (HSN), silvergold core shell (Ag@Au), goldsilver core shell (Au@Ag), and silvergold alloy nanoparticles (Ag/Au). Among these nanomaterials, Ag@Au core shell NPs are advantageous for aptasensing applications because the core improves the physical properties and the shell provides chemical stability and biocompatibility for the immobilization of aptamers. Self-assembly of the NPs on a cysteamine film at the surface of a carbon paste electrode is followed by the immobilization of thiolated aptamers at these nanoframes. The nanostructured (Ag@Au) aptadevice for Escherichia coli as a target shows four times better performance in comparison to the response obtained at an aptamer modified planar gold electrode. A comparison with other (core shell) NPs is performed by cyclic voltammetry and differential pulse voltammetry. Also, the selectivity of the aptasensor is investigated using other kinds of bacteria. The synthesized NPs and the morphology of the modified electrode are characterized by UV-Vis absorption spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, and electrochemical impedance spectroscopy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000382480000006 Publication Date 2016-08-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2227-9040 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 9 Open Access
Notes (up) ; Ezat Hamidi-Asl was financially supported by Belspo (University of Antwerp). The authors are thankful to Femke De Croock for her technical support and to Stanislav Trashin for his worthwhile comments on the manuscript. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:135411 Serial 5886
Permanent link to this record
 

 
Author Hamidi-Asl, E.; Dardenne, F.; Blust, R.; De Wael, K.
Title An improved electrochemical aptasensor for chloramphenicol detection based on aptamer incorporated gelatine Type A1 Journal article
Year 2015 Publication Sensors Abbreviated Journal Sensors-Basel
Volume 15 Issue 4 Pages 7605-7618
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Because of the biocompatible properties of gelatine and the good affinity of aptamers for their targets, the combination of aptamer and gelatine type B is reported as promising for the development of biosensing devices. Here, an aptamer for chloramphenicol (CAP) is mixed with different types of gelatine and dropped on the surface of disposable gold screen printed electrodes. The signal of the CAP reduction is investigated using differential pulse voltammetry. The diagnostic performance of the sensor is described and a detection limit of 1.83 x 10(-10) M is found. The selectivity and the stability of the aptasensor are studied and compared to those of other CAP sensors described in literature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000354236100025 Publication Date 2015-03-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1424-8220 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.677 Times cited 21 Open Access
Notes (up) ; Ezat Hamidi-Asl was financially supported by IOF-POC (University of Antwerp). ; Approved Most recent IF: 2.677; 2015 IF: 2.245
Call Number UA @ admin @ c:irua:126071 Serial 5464
Permanent link to this record
 

 
Author Bottari, F.; Moro, G.; Sleegers, N.; Florea, A.; Cowen, T.; Piletsky, S.; van Nuijs, A.L.N.; De Wael, K.
Title Electropolymerized o-phenylenediamine on graphite promoting the electrochemical detection of nafcillin Type A1 Journal article
Year 2019 Publication Electroanalysis Abbreviated Journal Electroanal
Volume 32 Issue 32 Pages 135-141
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre
Abstract By combining molecular modelling and electrochemistry we envision the creation of modified electrodes tailored for a more sensitive and selective detection of a single analyte. In this study we report on a graphite screen printed electrode modified with electropolymerized o-phenylenediamine, selected by rational design, which promotes the detection of nafcillin (NAF), an antibiotic. Parameters such as monomer concentration, pH and number of electropolymerization cycles were optimized to obtain the highest current signal for the target upon amperometric detection. NAF identification was based on the redox process at +1.1 V (vs pseudo Ag), ascribed to the oxidation of the C-7 side chain. With the optimized modification protocol, a two-fold increase in nafcillin signal could be obtained: the calibration plot in 0.1 M Britton-Robinson buffer pH 4 showed a limit of detection of 80 nM with improved sensitivity and reproducibility (RSD<5 %) compared to the detection at non-modified electrodes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000482596300001 Publication Date 2019-08-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1040-0397 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.851 Times cited 1 Open Access
Notes (up) ; FB and GM devised the study and performed the experiments, FB wrote the original draft of the paper and analysed the data, NS and AvN performed the MS experiments, AF helped with the optimization of the protocol and correction of the first draft, TC and SP performed the rational monomer design, KdW supervised the work and corrected the final draft. All authors gave their suggestions and corrections to the final version of the paper. This work was financially supported by the University of Antwerp (BOF) and the Research Foundation Flanders (FWO). ; Approved Most recent IF: 2.851
Call Number UA @ admin @ c:irua:162870 Serial 5601
Permanent link to this record
 

 
Author De Wael, K.; Daems, D.; Van Camp, G.; Nagels, L.J.
Title The use of potentiometric sensors to study (bio)molecular interactions Type A1 Journal article
Year 2012 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 84 Issue 11 Pages 4921-4927
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Potentiometric sensors were used to study molecular interactions in liquid environments, with sensorgram methodology. This is demonstrated with a lipophilic rubber-, and with a collagen based hydrogel sensor coating. The investigated molecules were promazine and tartaric acid respectively. The sensors were placed in a hydrodynamic wall jet system for the recording of sensorgrams. mV sensor responses were first converted to a signal, expressing the concentration of adsorbed organic ions. Using a linearization method, a pseudo first order kinetic model of adsorption was shown to fit the experimental results perfectly. Kass, kon and koff values were calculated.. The technique can be used over 4 decades of concentration, and it is very sensitive to low MW compounds as well as to multiply charged large biomolecules. This study is the first to demonstrate the application of potentiometric sensors as an alternative and complement to SPR methods.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000304783100041 Publication Date 2012-04-28
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 10 Open Access
Notes (up) ; Financial support for this work was provided by the University of Antwerp by granting D.D. a BOF interdisciplinary research project. We thank J. Everaert for his help in interpreting the results. K.D.W. and D.D. contributed equally to this work. ; Approved Most recent IF: 6.32; 2012 IF: 5.695
Call Number UA @ admin @ c:irua:97520 Serial 5898
Permanent link to this record
 

 
Author Hamidi-Asl, E.; Daems, D.; De Wael, K.; Van Camp, G.; Nagels, L.J.
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
Volume 86 Issue 24 Pages 12243-12249
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000346683900048 Publication Date 2014-11-13
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 10 Open Access
Notes (up) ; 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
Call Number UA @ admin @ c:irua:120164 Serial 5548
Permanent link to this record
 

 
Author Daems, D.; De Wael, K.; Vissenberg, K.; Van Camp, G.; Nagels, L.
Title Potentiometric sensors doped with biomolecules as a new approach to small molecule/biomolecule binding kinetics analysis Type A1 Journal article
Year 2014 Publication Biosensors and bioelectronics Abbreviated Journal Biosens Bioelectron
Volume 54 Issue Pages 515-520
Keywords A1 Journal article; Engineering sciences. Technology; Integrated Molecular Plant Physiology Research (IMPRES); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The most successful binding kinetics analysis systems at this moment include surface plasmon resonance (SPR), quartz microcrystal balance (QMB) and surface acoustic wave (SAW). Although these are powerful methods, they generally are complex, expensive and require the use of monolayers. Here, we report on potentiometric sensors as an inexpensive and simple alternative to do binding kinetics analysis between small molecules in solution and biomolecules (covalently) attached in a biopolymer sensor coating layer. As an example, dopamine and an anti-dopamine aptamer were used as the small molecule and the biomolecule respectively. Binding between both follows a Langmuir adsorption type model and creates a surface potential. The system operates in Flow Injection Analysis mode (FIA). Besides being an interesting new binding kinetics tool, the approach allows systematic design of potentiometric biosensors (in the present study a dopamine sensor), and gives new insights into the functioning of ion-selective electrodes (ISEs).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000333071500077 Publication Date 2013-11-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0956-5663 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.78 Times cited 10 Open Access
Notes (up) ; Financial support for this work was provided by the University of Antwerp by granting L.N. and G.V.C. a BOF interdisciplinary research project. ; Approved Most recent IF: 7.78; 2014 IF: 6.409
Call Number UA @ admin @ c:irua:111678 Serial 5780
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.
Address
Corporate Author Thesis
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 (up) ; 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 Rather, J.A.; Debnath, P.; De Wael, K.
Title Fullerene-\beta-cyclodextrin conjugate based electrochemical sensing device for ultrasensitive detection of p-nitrophenol Type A1 Journal article
Year 2013 Publication Electroanalysis Abbreviated Journal Electroanal
Volume 25 Issue 9 Pages 2145-2150
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The article describes the use of a fullerene (C60)-β-cyclodextrin conjugate, synthesized via 1,3-dipolar cycloaddition, for the ultrasensitive electrochemical detection of p-nitrophenol. This conjugate was successfully immobilized on the surface of a glassy carbon electrode and the developed device showed high activity towards p-nitrophenol due to the synergetic effect of C60, the latter becoming highly conductive upon reduction. The determination of p-nitrophenol was performed by using square wave voltammetry over a concentration range from 2.8×10−9 mol L−1 to 4.2×10−7 mol L−1 and the detection limit was calculated to be 1.2×10−9 mol L−1.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000327590600017 Publication Date 2013-08-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1040-0397 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.851 Times cited 13 Open Access
Notes (up) ; Jahangir Ahmad Rather is highly thankful for mobility grant provided by the Belspo co-funded by Marie Curie Actions. ; Approved Most recent IF: 2.851; 2013 IF: 2.502
Call Number UA @ admin @ c:irua:110033 Serial 5629
Permanent link to this record
 

 
Author De Wael, K.; Bashir, Q.; van Vlierberghe, S.; Dubruel, P.; Heering, H.A.; Adriaens, A.
Title Electrochemical determination of hydrogen peroxide with cytochrome c peroxidase and horse heart cytochrome c entrapped in a gelatin hydrogel Type A1 Journal article
Year 2012 Publication Bioelectrochemistry: an international journal devoted to electrochemical aspects of biology and biological aspects of electrochemistry Abbreviated Journal Bioelectrochemistry
Volume 83 Issue Pages 15-18
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract A novel and versatile method, based on a membrane-free enzyme electrode in which both the enzyme and a mediator protein are entrapped in a gelatine hydrogel was developed for the fabrication of biosensors. As a proof of principle, we prepared a hydrogen peroxide biosensor by successfully entrapping both horse heart cytochrome c (HHC) and Saccharomyces cerevisae cytochrome c peroxidase (CCP) in a gelatin matrix which is immobilized on a gold electrode. This electrode was first pretreated with 6-mercaptohexanol. The biosensor displayed a rapid response and an expanded linear response range from 0 to 0.3 mM (R = 0.987) with a detection limit of 1 × 10− 5 M in a HEPES buffer solution (pH 7.0). This method of encapsulation is now further investigated for industrial biosensor applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000297962500003 Publication Date 2011-08-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1567-5394 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.346 Times cited 31 Open Access
Notes (up) ; Karolien De Wael is grateful to the Research Foundation-Flanders (FWO, Belgium) for her postdoctoral fellowship. ; Approved Most recent IF: 3.346; 2012 IF: 3.947
Call Number UA @ admin @ c:irua:92067 Serial 5589
Permanent link to this record
 

 
Author Qurashi, A.; Rather, J.A.; De Wael, K.; Merzougui, B.; Tabet, N.; Faiz, M.
Title Rapid microwave synthesis of high aspect-ration ZnO nanotetrapods for swift bisphenol A detection Type A1 Journal article
Year 2013 Publication The analyst Abbreviated Journal Analyst
Volume 138 Issue 17 Pages 4764-4768
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000322389600011 Publication Date 2013-05-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-2654 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.885 Times cited 15 Open Access
Notes (up) ; One of the authors (Jahangir Ahmad Rather) is highly thankful for the mobility grant (Non-Europe Postdoc Fellowship) supported by the Belgian Federal Science Policy (Belspo) co-funded by the Marie Curie Actions from the European Commission. ; Approved Most recent IF: 3.885; 2013 IF: 3.906
Call Number UA @ admin @ c:irua:108959 Serial 5801
Permanent link to this record
 

 
Author Tilleman, L.; De Henau, S.; Pauwels, M.; Nagy, N.; Pintelon, I.; Braeckman, B.P.; De Wael, K.; Van Doorslaer, S.; Adriaensen, D.; Timmermans, J.-P.; Moens, L.; Dewilde, S.
Title An N-myristoylated globin with a redox-sensing function that regulates the defecation cycle in Caenorhabditis elegans Type A1 Journal article
Year 2012 Publication PLoS ONE Abbreviated Journal Plos One
Volume 7 Issue 12 Pages e48768-9
Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Globins occur in all kingdoms of life where they fulfill a wide variety of functions. In the past they used to be primarily characterized as oxygen transport/storage proteins, but since the discovery of new members of the globin family like neuroglobin and cytoglobin, more diverse and complex functions have been assigned to this heterogeneous family. Here we propose a function for a membrane-bound globin of C. elegans, GLB-26. This globin was predicted to be myristoylated at its N-terminus, a post-translational modification only recently described in the globin family. In vivo, this globin is found in the membrane of the head mesodermal cell and in the tail stomato-intestinal and anal depressor muscle cells. Since GLB-26 is almost directly oxidized when exposed to oxygen, we postulate a possible function as electron transfer protein. Phenotypical studies show that GLB-26 takes part in regulating the length of the defecation cycle in C. elegans under oxidative stress conditions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000313236200008 Publication Date 2012-12-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-6203 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.806 Times cited 6 Open Access
Notes (up) ; SDH is a Ph.D. fellow of the Fund for Scientific Research (FWO). Financial support to SD and LM was provided by the University of Antwerp (BOF UA TOP 2006) and to SD, LM, BPB, by FWO project G.0247.09. The UltraVIEW VoX spinning disk confocal microscope was purchased with support of the Hercules Foundation (Hercules Type 1: AUHA 09/001). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ; Approved Most recent IF: 2.806; 2012 IF: 3.730
Call Number UA @ admin @ c:irua:102591 Serial 5741
Permanent link to this record
 

 
Author Trashin, S.; De Jong, M.; Breugelmans, T.; Pilehvar, S.; De Wael, K.
Title Label-free impedance aptasensor for major peanut allergen Ara h 1 Type A1 Journal article
Year 2015 Publication Electroanalysis Abbreviated Journal
Volume 27 Issue 1 Pages 32-37
Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Applied Electrochemistry & Catalysis (ELCAT)
Abstract The peanut allergen Ara h 1 belonging to the vicilin family of seed storage proteins is known to be a suitable marker for peanut detection in foods. In the present work, we suggest an electrochemical detection of Ara h 1 using a recently selected 80-base DNA aptamer. The detection strategy relies on insulation effect of a bulky protein captured by an immobilized aptamer. The electrodes were modified by the aptamer and characterized using electrochemical impedance spectroscopy (EIS). The aptamer surface density and analytical parameters of the calibration curves for Ara h 1 were compared with the system prepared with thrombin binding aptamer (TBA) and operated in the same conditions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000347838300004 Publication Date 2014-10-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 10 Open Access
Notes (up) ; ST greatly appreciates the Research Council University of Antwerp (IWS BOF UA) for funding the post-doctoral fellowship. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:119442 Serial 5686
Permanent link to this record
 

 
Author Dubinina, T.V.; Moiseeva, E.O.; Astvatsaturov, D.A.; Borisova, N.E.; Tarakanov, P.A.; Trashin, S.A.; De Wael, K.; Tomilova, L.G.
Title Novel 2-naphthyl substituted zinc naphthalocyanine : synthesis, optical, electrochemical and spectroelectrochemical properties Type A1 Journal article
Year 2020 Publication New Journal Of Chemistry Abbreviated Journal New J Chem
Volume 44 Issue 19 Pages 7849-7857
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract New zinc naphthalocyanine with bulky 2-naphthyl groups was obtained. Aggregation drastically influences its optical and electrochemical behavior. Spectroelectrochemistry helps to establish the oxidation potential and reveals unusual color change.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000536157700023 Publication Date 2020-04-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1144-0546 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.3 Times cited 1 Open Access
Notes (up) ; Synthesis, identification and optical studies of target compounds were supported by the Russian Science Foundation Grant No 19-73-00099. Electrochemical and spectroelectrochemical measurements were supported by ERA.Net RUS Plus Plasmon Electrolight and FWO funding (RFBR No 18-53-76006 ERA). Fluorescence studies were supported by the Council under the President of the Russian Federation for State Support of Young Scientists and Leading Scientific Schools (Grant MD-3847.2019.3). The NMR spectroscopic measurements were carried out in the Laboratory of Magnetic Tomography and Spectroscopy, Faculty of Fundamental Medicine of Moscow State University. ; Approved Most recent IF: 3.3; 2020 IF: 3.269
Call Number UA @ admin @ c:irua:168952 Serial 6570
Permanent link to this record
 

 
Author De Jong, M.; Sleegers, N.; Kim, J.; Van Durme, F.; Samyn, N.; Wang, J.; De Wael, K.
Title Electrochemical fingerprint of street samples for fast on-site screening of cocaine in seized drug powders Type A1 Journal article
Year 2016 Publication Chemical science Abbreviated Journal Chem Sci
Volume Issue Pages 1-7
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract We report on a wearable fingertip sensor for on-the-spot identification of cocaine and its cutting agents in street samples. Traditionally, on-site screening is performed by means of colour tests which are difficult to interpret and lack selectivity. By presenting the distinct voltammetric response of cocaine, cutting agents, binary mixtures of cocaine and street samples in solution and powder street samples, we were able to elucidate the electrochemical fingerprint of all these compounds. The new electrochemical concept holds considerable promise as an on-site screening method.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000371021900094 Publication Date 2016-01-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-6520 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.668 Times cited 37 Open Access
Notes (up) ; The authors acknowledge BELSPO for funding the APTADRU project (BR/314/PI/ APTADRU). ; Approved Most recent IF: 8.668
Call Number UA @ admin @ c:irua:130404 Serial 5591
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.
Address
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 (up) ; 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 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.
Address
Corporate Author Thesis
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 (up) ; 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
Permanent link to this record
 

 
Author Anaf, W.; Janssens, K.; De Wael, K.
Title Formation of metallic mercury during photodegradation/photodarkening of \alpha-HgS : electrochemical evidence Type A1 Journal article
Year 2013 Publication Angewandte Chemie: international edition in English Abbreviated Journal Angew Chem Int Edit
Volume 52 Issue 48 Pages 12568-12571
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Das rote Pigment α-HgS neigt in Gegenwart von Licht und Chloridionen zur Schwärzung. Als Grund für die Zersetzung und Entfärbung werden die Bildung von (schwarzem) β-HgS oder Quecksilbermetall vermutet, doch diese Substanzen wurden noch nicht auf natürlich oder künstlich zersetzter HgS-Farbe nachgewiesen. Elektrochemische Experimente belegen nun die Bildung von Quecksilbermetall in Gegenwart von Licht und Chloridionen.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000327582900015 Publication Date 2013-10-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1433-7851; 0570-0833 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 11.994 Times cited 19 Open Access
Notes (up) ; The authors acknowledge L. Klaassen for valuable discussions and providing samples. We acknowledge financial support from the SDD programme (S2-ART project) of the Belgian Federal Goverment. ; Approved Most recent IF: 11.994; 2013 IF: 11.336
Call Number UA @ admin @ c:irua:111265 Serial 5626
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.
Address
Corporate Author Thesis
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 (up) ; 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 Anaf, W.; Schalm, O.; Janssens, K.; De Wael, K.
Title Understanding the (in)stability of semiconductor pigments by a thermodynamic approach Type A1 Journal article
Year 2015 Publication Dyes and pigments Abbreviated Journal Dyes Pigments
Volume 113 Issue Pages 409-415
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES)
Abstract Several artists pigments are semiconductors. Some of these materials appear stable over time, whereas others already show remarkable signs of degradation after limited time periods. The (in)stability of these pigments can be understood using a thermodynamic approach. For several pigment-related materials, the thermodynamic oxidation and reduction potential (ϕox and ϕred) were determined and evaluated considering the absolute energy positions of the valence and conduction band edges and the water redox potentials. The positions of ϕox and ϕred can be used in a fast screening of the stability of semiconductor pigments towards photoinduced corrosion in an aqueous/humid environment. This theoretical approach corresponds well with experimental data on pigment permanence and degradation phenomena found in literature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000346543200052 Publication Date 2014-09-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0143-7208 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.473 Times cited 14 Open Access
Notes (up) ; The authors acknowledge the funding from the Belspo S2-ART project (Belgian Federal Government) SD/RI/04A. ; Approved Most recent IF: 3.473; 2015 IF: 3.966
Call Number UA @ admin @ c:irua:118875 Serial 5885
Permanent link to this record
 

 
Author Cuypers, B.; Vermeylen, S.; Hammerschmid, D.; Trashin, S.; Rahemi, V.; Konijnenberg, A.; De Schutter, A.; Cheng, C.-H.C.; Giordano, D.; Verde, C.; De Wael, K.; Sobott, F.; Dewilde, S.; Van Doorslaer, S.
Title Antarctic fish versus human cytoglobins : the same but yet so different Type A1 Journal article
Year 2017 Publication Journal of inorganic biochemistry Abbreviated Journal J Inorg Biochem
Volume 173 Issue Pages 66-78
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The cytoglobins of the Antarctic fish Chaenocephalus aceratus and Dissostichus mawsoni have many features in common with human cytoglobin. These cytoglobins are heme proteins in which the ferric and ferrous forms have a characteristic hexacoordination of the heme iron, i.e. axial ligation of two endogenous histidine residues, as confirmed by electron paramagnetic resonance, resonance Raman and optical absorption spectroscopy. The combined spectroscopic analysis revealed only small variations in the heme-pocket structure, in line with the small variations observed for the redox potential. Nevertheless, some striking differences were also discovered. Resonance Raman spectroscopy showed that the stabilization of an exogenous heme ligand, such as CO, occurs differently in human cytoglobin in comparison with Antarctic fish cytoglobins. Furthermore, while it has been extensively reported that human cytoglobin is essentially monomeric and can form an intramolecular disulfide bridge that can influence the ligand binding kinetics, 3D modeling of the Antarctic fish cytoglobins indicates that the cysteine residues are too far apart to form such an intramolecular bridge. Moreover, gel filtration and mass spectrometry reveal the occurrence of non-covalent multimers (up to pentamers) in the Antarctic fish cytoglobins that are formed at low concentrations. Stabilization of these oligomers by disulfide-bridge formation is possible, but not essential. If intermolecular disulfide bridges are formed, they influence the heme-pocket structure, as is shown by EPR measurements.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000405159600007 Publication Date 2017-04-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0162-0134 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.348 Times cited 7 Open Access
Notes (up) ; The authors acknowledge the support of the University of Antwerp GOA-BOF funding (28312), FWO funding (G.0687.13) and the Hercules foundation for funding of the Synapt G2 instrument. This study was carried out in the framework of the SCAR program “Antarctic Thresholds – Ecosystem Resilience and Adaptation” (AnT-ERA). It was financially supported by the Italian National Program for Antarctic Research (PNRA). Research of A. De Schutter is funded by a PhD grant of the Agency for Innovation by Science and Technology (121339) (IWT, Belgium). C-H C. Cheng acknowledges funding support from US National Science Foundation Polar Programs (ANT-1142158). ; Approved Most recent IF: 3.348
Call Number UA @ admin @ c:irua:144826 Serial 5474
Permanent link to this record
 

 
Author Rather, J.A.; De Wael, K.
Title Fullerene-C60 sensor for ultra-high sensitive detection of bisphenol-A and its treatment by green technology Type A1 Journal article
Year 2013 Publication Sensors and actuators : B : chemical Abbreviated Journal Sensor Actuat B-Chem
Volume 176 Issue Pages 110-117
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Endocrine disruptors (EDCs) are environmental pollutants that, once incorporated into an organism, affect the hormonal balance of humans and various species. Its presence in environment is of great importance in water quality related questions. The proposed method describes the development of an accurate, sensitive and selective sensor for the detection of bisphenol-A (BPA) and its treatment by green technology. A fullerene (C60) fabricated electrochemical sensor was developed for the ultrasensitive detection of BPA. The homemade sensor was characterized by scanning electron microscopy, electrochemical impedance spectroscopy and chronocoulometry. The influence of measuring parameters such as pH and C60 loading on the analytical performance of the sensor was evaluated. Various kinetic parameters such as electron transfer number (n); charge transfer coefficient (α); electrode surface area (A) and diffusion coefficient (D) were also calculated. Under the optimal conditions, the oxidation peak current was linear over the concentration range of 74 nM to 0.23 μM with the detection limit (LOD) of 3.7 nM. The fabricated sensor was successfully applied to the determination of BPA in wastewater samples and it has promising analytical applications for the direct determination of BPA at trace level.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000319867500017 Publication Date 2012-09-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-4005 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.401 Times cited 79 Open Access
Notes (up) ; The authors are highly thankful for the mobility grant (Non-Europe Postdoc Fellowship) for one of the author (Jahangir Ahmad Rather) supported by the Belgian Federal Science Policy (Belspo) co-funded by the Marie Curie Actions from the European Commission. ; Approved Most recent IF: 5.401; 2013 IF: 3.840
Call Number UA @ admin @ c:irua:101055 Serial 5630
Permanent link to this record
 

 
Author Rather, J.A.; Pilehvar, S.; De Wael, K.
Title Polycyclodextrin and carbon nanotubes as composite for tyrosinase immobilization and its superior electrocatalytic activity towards butylparaben an endocrine disruptor Type A1 Journal article
Year 2015 Publication Journal of nanoscience and nanotechnology Abbreviated Journal
Volume 15 Issue 5 Pages 3365-3372
Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract We developed a protocol for the immobilization of tyrosinase (Tyr) on the composite of polycyclodextrin polymer (CDP) and carbon nanotubes for the detection of an endocrine disruptor, i.e., butylparaben (BP). The formation of the CDP polymer was characterized by UV-Vis spectrophotometry. The conducting film of cross-linked CDP and carbon nanotubes, displays excellent matrix capabilities for Tyr immobilization. The host-guest chemical reaction ability of CD and the ππ stacking interaction assure the bioactivity of Tyr towards butylparaben. The developed biosensor was characterized electrochemically by electrochemical impedance spectroscopy. The enzyme-substrate kinetic parameters such as the apparent Michaelis-Menten constant (K M app) was measured under saturated substrate concentration. The determination of butylparaben was carried out by using square wave voltammetry over the concentration range of 2.1 to 35.4 μM with a detection limit of 0.1 μM. The fabricated biosensor was successfully applied in real-life cosmetic samples with good recovery ranging from 98.5 to 102.8%.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000347435200007 Publication Date 2014-10-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1533-4899 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 3 Open Access
Notes (up) ; The authors are highly thankful for the mobility grant (Non-Europe Postdoc Fellowship) for one of the author (Jahangir Ahmad Rather) supported by the Belgian Federal Science Policy (Belspo) co-funded by the Marie Curie Actions from the European Commission. Sanaz Pilehvar is funded by BOF-DOCPRO UA. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:119550 Serial 5776
Permanent link to this record