| Records |
| Author |
Trashin, S.; De Jong, M.; Luyckx, E.; Dewilde, S.; De Wael, K. |
| Title |
Electrochemical evidence for neuroglobin activity on NO at physiological concentrations |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Journal of biological chemistry |
Abbreviated Journal |
J Biol Chem |
| Volume |
291 |
Issue |
36 |
Pages |
18959-18966 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract  |
The true function of neuroglobin (Ngb) and, particularly, human Ngb (NGB) has been under debate since its discovery 15 years ago. It has been expected to play a role in oxygen binding/supply, but a variety of other functions have been put forward, including NO dioxygenase activity. However, in vitro studies that could unravel these potential roles have been hampered by the lack of an Ngb-specific reductase. In this work, we used electrochemical measurements to investigate the role of an intermittent internal disulfide bridge in determining NO oxidation kinetics at physiological NO concentrations. The use of a polarized electrode to efficiently interconvert the ferric (Fe3+) and ferrous (Fe2+) forms of an immobilized NGB showed that the disulfide bridge both defines the kinetics of NO dioxygenase activity and regulates appearance of the free ferrous deoxy-NGB, which is the redox active form of the protein in contrast to oxy-NGB. Our studies further identified a role for the distal histidine, interacting with the hexacoordinated iron atom of the heme, in oxidation kinetics. These findings may be relevant in vivo, for example in blocking apoptosis by reduction of ferric cytochrome c, and gentle tuning of NO concentration in the tissues. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000383242300031 |
Publication Date |
2016-07-12 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
|
Edition |
|
| ISSN |
0021-9258; 1083-351x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.125 |
Times cited |
11 |
Open Access |
|
| Notes |
; This work was supported by Fonds Wetenschappelijk Onderzoek (FWO) Grant G.0687.13 and Universiteit Antwerpen GOA BOF 28312. The authors declare that they have no conflicts of interest with the contents of this article. ; |
Approved |
Most recent IF: 4.125 |
| Call Number |
UA @ admin @ c:irua:134340 |
Serial |
5590 |
| Permanent link to this record |
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| |
| Author |
Blidar, A.; Trashin, S.; Carrion, E.N.; Gorun, S.M.; Cristea, C.; De Wael, K. |
| Title |
Enhanced photoelectrochemical detection of an analyte triggered by its concentration by a singlet oxygen-generating fluoro photosensitizer |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Acs Sensors |
Abbreviated Journal |
Acs Sensors |
| Volume |
5 |
Issue |
11 |
Pages |
3501-3509 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The use of a photocatalyst (photosensitizer) which produces singlet oxygen instead of enzymes for oxidizing analytes creates opportunities for designing cost-efficient and sensitive photoelectrochemical sensors. We report that perfluoroisopropyl-substituted zinc phthalocyanine (F64PcZn) interacts specifically with a complex phenolic compound, the antibiotic rifampicin (RIF), but not with hydroquinone or another complex phenolic compound, the antibiotic doxycycline. The specificity is imparted by the selective preconcentration of RIF in the photocatalytic layer, as revealed by electrochemical and optical measurements, complemented by molecular modeling that confirms the important role of a hydrophobic cavity formed by the iso-perfluoropropyl groups of the photocatalyst. The preconcentration effect favorably enhances the RIF photoelectrochemical detection limit as well as sensitivity to nanomolar (ppb) concentrations, LOD = 7 nM (6 ppb) and 2.8 A.M-1.cm(-2), respectively. The selectivity to RIF, retained in the photosensitizer layer, is further enhanced by the selective removal of all unretained phenols via simple washing of the electrodes with pure buffer. The utility of the sensor for analyzing municipal wastewater was demonstrated. This first demonstration of enhanced selectivity and sensitivity due to intrinsic interactions of a molecular photocatalyst (photosensitizer) with an analyte, without use of a biorecognition element, may allow the design of related, robust, simple, and viable sensors. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000595550100021 |
Publication Date |
2020-10-29 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
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Edition |
|
| ISSN |
2379-3694 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
8.9 |
Times cited |
|
Open Access |
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| Notes |
|
Approved |
Most recent IF: 8.9; 2020 IF: NA |
| Call Number |
UA @ admin @ c:irua:176057 |
Serial |
7913 |
| Permanent link to this record |
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| Author |
Neven, L.; Thiruvottriyur Shanmugam, S.; Rahemi, V.; Trashin, S.; Sleegers, N.; Carrion, E.N.; Gorun, S.M.; De Wael, K. |
| 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 |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000480499200086 |
Publication Date |
2019-06-25 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
|
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 |
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| Notes |
; FWO and UA-BOF are acknowledged for financial support. The Center for Functional Materials of Seton Hall University is thanked for support (S.M.G. and E.N.C.). Joren Van Loon is thanked for the graphical abstract. This research was supported by the medium scale research infrastructure funding Hercules funding (SEM). ; |
Approved |
Most recent IF: 6.32 |
| Call Number |
UA @ admin @ c:irua:161831 |
Serial |
5763 |
| Permanent link to this record |
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| Author |
Rahemi, V.; Trashin, S.; Hafideddine, Z.; Meynen, V.; Van Doorslaer, S.; De Wael, K. |
| Title |
Enzymatic sensor for phenols based on titanium dioxide generating surface confined ROS after treatment with H2O2 |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
| Volume |
283 |
Issue |
283 |
Pages |
343-348 |
| Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Titanium dioxide (TiO2) is a popular material as host matrix for enzymes. We now evidence that TiO2 can accumulate and retain reactive oxygen species after treatment by hydrogen peroxide (H2O2) and support redox cycling of a phenolic analyte between horseradish peroxidase (HRP) and an electrode. The proposed detection scheme is identical to that of second generation biosensors, but the measuring solution requires no dissolved H2O2. This significantly simplifies the analysis and overcomes issues related to H2O2 being present (or generated) in the solution. The modified electrodes showed rapid stabilization of the baseline, a low noise level, fast realization of a steady-state current response, and, in addition, improved sensitivity and limit of detection compared to the conventional approach, i.e. in the presence of H2O2 in the measuring solution. Hydroquinone, 4-aminophenol, and other phenolic compounds were successfully detected at sub-μM concentrations. Particularly, a linear response in the concentration range between 0.025 and 2 μM and LOD of 24 nM was demonstrated for 4-aminophenol. The proposed sensor design goes beyond the traditional concept with three sensors generations offering a new possibility for the development of enzymatic sensors based on peroxidases and the formation of ROS on titania after treatment with H2O2. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000455854000043 |
Publication Date |
2018-12-10 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0925-4005 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.401 |
Times cited |
1 |
Open Access |
|
| Notes |
; The authors thank the University of Antwerp for GOA funding and the Scientific Research-Flanders (FWO) (grant 12T4219N). V. Rahemi is financially supported through a postdoctoral fellowship of the Research Foundation-Flanders (FWO). ; |
Approved |
Most recent IF: 5.401 |
| Call Number |
UA @ admin @ c:irua:155665 |
Serial |
5605 |
| Permanent link to this record |
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| Author |
Rahemi, V.; Trashin, S.; Hafideddine, Z.; Van Doorslaer, S.; Meynen, V.; Gorton, L.; De Wael, K. |
| Title |
Amperometric flow-injection analysis of phenols induced by reactive oxygen species generated under daylight irradiation of titania impregnated with horseradish peroxidase |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
92 |
Issue |
92 |
Pages |
3643-3649 |
| Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Titanium dioxide (TiO2) is a unique material for biosensing applications due to its capability of hosting enzymes. For the first time, we show that TiO2 can accumulate reactive oxygen species (ROS) under daylight irradiation and can support the catalytic cycle of horseradish peroxidase (HRP) without the need of H2O2 to be present in the solution. Phenolic compounds, such as hydroquinone (HQ) and 4-aminophenol (4-AP), were detected amperometrically in flow-injection analysis (FIA) mode via the use of an electrode modified with TiO2 impregnated with HRP. In contrast to the conventional detection scheme, no H2O2 was added to the analyte solution. Basically, the inherited ability of TiO2 to generate reactive oxygen species is used as a strategy to avoid adding H2O2 in the solution during the detection of phenolic compounds. Electron paramagnetic resonance (EPR) spectroscopy indicates the presence of ROS on titania which, in interaction with HRP, initiate the electrocatalysis toward phenolic compounds. The amperometric response to 4-AP was linear in the concentration range between 0.05 and 2 μM. The sensitivity was 0.51 A M–1 cm–2, and the limit of detection (LOD) 26 nM. The proposed sensor design opens new opportunities for the detection of phenolic traces by HRP-based electrochemical biosensors, yet in a more straightforward and sensitive way following green chemistry principles of avoiding the use of reactive and harmful chemical, such as H2O2. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000518234700023 |
Publication Date |
2020-01-27 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
7.4 |
Times cited |
3 |
Open Access |
|
| Notes |
; The authors thank Scientific Reseatch-Flanders (F-WO) (grant 12T4219N) for funding. ; |
Approved |
Most recent IF: 7.4; 2020 IF: 6.32 |
| Call Number |
UA @ admin @ c:irua:166241 |
Serial |
5463 |
| Permanent link to this record |
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| Author |
Khan, S.U.; Trashin, S.A.; Korostei, Y.S.; Dubinina, T.V.; Tomilova, L.G.; Verbruggen, S.W.; De Wael, K. |
| Title |
Photoelectrochemistry for measuring the photocatalytic activity of soluble photosensitizers |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
ChemPhotoChem |
Abbreviated Journal |
|
| Volume |
4 |
Issue |
4 |
Pages |
300-306 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Sustainable Energy, Air and Water Technology (DuEL) |
| Abstract |
We introduce a rapid method to test the photocatalytic activity of singlet‐oxygen‐producing photosensitizers using a batch cell, a LED laser and a conventional potentiostat. The strategy is based on coupling of photo‐oxidation of hydroquinone and simultaneous electrochemical reduction of its oxidized form at a carbon electrode in an organic solvent (methanol). This scheme gives an immediate response and avoids complications related to long‐term experiments such as oxidative photo‐degradation of photosensitizers and singlet oxygen traps by reactive oxygen species (ROS). Among the tested compounds, a fluoro‐substituted subphthalocyanine showed the highest photocurrent and singlet oxygen quantum yield (ΦΔ) in comparison to phenoxy‐ and tert‐butyl‐substituted analogues, whereas the lowest photocurrents and yields were observed for aggregated and dimeric phthalocyanine complexes. The method is useful for fast screening of the photosensitizing activity and represents the first example of one‐pot coupling of electrochemical and photocatalytic reactions in organic media. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000520100400001 |
Publication Date |
2020-01-25 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2367-0932 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
|
| Notes |
; We gratefully acknowledge the financial support by ERA.Net RUS Plus Plasmon Electrolight project (No. 18-53-76006 ERA) and RSF 17-13-01197. ; |
Approved |
Most recent IF: 3.7; 2020 IF: NA |
| Call Number |
UA @ admin @ c:irua:165912 |
Serial |
5771 |
| Permanent link to this record |
