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Author |
Thiruvottriyur Shanmugam, S.; Trashin, S.; De Wael, K. |
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Title |
Singlet oxygen-based photoelectrochemical detection of DNA |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Biosensors and bioelectronics |
Abbreviated Journal |
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Volume  |
195 |
Issue |
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Pages |
113652 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Abstract |
The current work, designed for the photoelectrochemical detection of DNA, evaluates light-responsive DNA probes carrying molecular photosensitizers generating singlet oxygen (1O2). We take advantage of their chromophore’s ability to produce 1O2 upon photoexcitation and subsequent photocurrent response. Type I, fluorescent and type II photosensitizers were studied using diode lasers at 406 nm blue, 532 nm green and 659 nm red lasers in the presensce and absence of a redox reporter, hydroquinone (HQ). Only type II photosensitizers (producing 1O2) resulted in a noticeable photocurrent in 1–4 nA range upon illumination, in particular, dissolved DNA probes labeled with chlorin e6 and erythrosine were found to give a well-detectable photocurrent response in the presence of HQ. Whereas, Type I photosensitizers and fluorescent chromophores generate negligible photocurrents (<0.15 nA). The analytical performance of the sensing system was evaluated using a magnetic beads-based DNA assay on disposable electrode platforms, with a focus to enhance the sensitivity and robustness of the technique in detecting complementary DNA targets. Amplified photocurrent responses in the range of 70–100 nA were obtained and detection limits of 17 pM and 10 pM were achieved using magnetic beads-captured chlorin e6 and erythrosine labeled DNA probes respectively. The presented novel photoelectrochemical detection can further be optimized and employed in applications for which enzymatic amplification such as polymerase chain reaction (PCR) is not applicable owing to their limitations and as an effective alternative to colorimetric detection when rapid detection of specific nucleic acid targets is required. |
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Wos |
000705223300003 |
Publication Date |
2021-09-23 |
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ISSN |
0956-5663 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Open Access |
OpenAccess |
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no |
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Call Number |
UA @ admin @ c:irua:181796 |
Serial |
8930 |
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Author |
Moiseeva, E.O.; Trashin, S.; Korostei, Y.S.; Khan, S.U.; Kosov, A.D.; De Wael, K.; Dubinina, T.V.; Tomilova, L.G. |
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Title |
Electrochemical and spectroelectrochemical studies of tert-butyl-substituted aluminum phthalocyanine |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Polyhedron |
Abbreviated Journal |
Polyhedron |
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Volume |
200 |
Issue |
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Pages |
115136 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Tetra-tert-butylphthalocyanine aluminum (III) chloride was studied by voltammetric and potential-resolved spectroelectrochemical methods in a non-coordinating solvent o-dichlorobenzene. Five redox transitions were found including two oxidation waves at 0.18 and 0.90 V and three reduction waves at −1.28, −1.65, and −2.63 V vs. Fc+/Fc. Electrochemical reversibility of the first oxidation and reduction processes was assessed by using the diagnostic criteria of cyclic voltammetry. First comprehensive spectroelectrochemical characterization of oxidation of the aluminum phthalocyanine is reported. Moreover, potential-resolved spectroelectrochemical titration revealed strong influence of aggregation on the UV–vis spectra and the half-wave potentials of the first oxidation transition and disclosed the presence of the partially oxidized complex in the initial solution, which noticeably affected the spectrum of the neutral form. |
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Wos |
000640386000006 |
Publication Date |
2021-03-02 |
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ISSN |
0277-5387 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.926 |
Times cited |
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Open Access |
OpenAccess |
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Most recent IF: 1.926 |
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Call Number |
UA @ admin @ c:irua:176389 |
Serial |
7860 |
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Author |
Rahemi, V.; Trashin, S.; Hafideddine, Z.; Meynen, V.; Van Doorslaer, S.; De Wael, K. |
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Title |
Enzymatic sensor for phenols based on titanium dioxide generating surface confined ROS after treatment with H2O2 |
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A1 Journal article |
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Year |
2019 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
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Volume |
283 |
Issue |
283 |
Pages |
343-348 |
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Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Titanium dioxide (TiO2) is a popular material as host matrix for enzymes. We now evidence that TiO2 can accumulate and retain reactive oxygen species after treatment by hydrogen peroxide (H2O2) and support redox cycling of a phenolic analyte between horseradish peroxidase (HRP) and an electrode. The proposed detection scheme is identical to that of second generation biosensors, but the measuring solution requires no dissolved H2O2. This significantly simplifies the analysis and overcomes issues related to H2O2 being present (or generated) in the solution. The modified electrodes showed rapid stabilization of the baseline, a low noise level, fast realization of a steady-state current response, and, in addition, improved sensitivity and limit of detection compared to the conventional approach, i.e. in the presence of H2O2 in the measuring solution. Hydroquinone, 4-aminophenol, and other phenolic compounds were successfully detected at sub-μM concentrations. Particularly, a linear response in the concentration range between 0.025 and 2 μM and LOD of 24 nM was demonstrated for 4-aminophenol. The proposed sensor design goes beyond the traditional concept with three sensors generations offering a new possibility for the development of enzymatic sensors based on peroxidases and the formation of ROS on titania after treatment with H2O2. |
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Wos |
000455854000043 |
Publication Date |
2018-12-10 |
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Edition |
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ISSN |
0925-4005 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.401 |
Times cited |
1 |
Open Access |
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Notes |
; The authors thank the University of Antwerp for GOA funding and the Scientific Research-Flanders (FWO) (grant 12T4219N). V. Rahemi is financially supported through a postdoctoral fellowship of the Research Foundation-Flanders (FWO). ; |
Approved |
Most recent IF: 5.401 |
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Call Number |
UA @ admin @ c:irua:155665 |
Serial |
5605 |
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Author |
Trashin, S.; De Jong, M.; Luyckx, E.; Dewilde, S.; De Wael, K. |
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Title |
Electrochemical evidence for neuroglobin activity on NO at physiological concentrations |
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A1 Journal article |
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Year |
2016 |
Publication |
Journal of biological chemistry |
Abbreviated Journal |
J Biol Chem |
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Volume |
291 |
Issue |
36 |
Pages |
18959-18966 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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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. |
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Wos |
000383242300031 |
Publication Date |
2016-07-12 |
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ISSN |
0021-9258; 1083-351x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.125 |
Times cited |
11 |
Open Access |
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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 |
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Call Number |
UA @ admin @ c:irua:134340 |
Serial |
5590 |
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Author |
Lybaert, J.; Trashin, S.; Maes, B.U.W.; De Wael, K.; Abbaspour Tehrani, K. |
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Title |
Cooperative electrocatalytic and chemoselective alcohol oxidation by Shvo's catalyst |
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A1 Journal article |
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Year |
2017 |
Publication |
Advanced synthesis and catalysis |
Abbreviated Journal |
Adv Synth Catal |
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Volume |
359 |
Issue |
6 |
Pages |
919-925 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Organic synthesis (ORSY) |
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Abstract |
A new electrocatalytic conversion of alcohols to ketones and aldehydes was developed based on an electrochemical study of Shvos complex. The oxidation of secondary alcohols was efficiently performed under mild conditions using a catalytic amount of Shvos catalyst, in combination with a sub-stoichiometric amount of 2,6-dimethoxy-1,4- benzoquinone in N,N-dimethylformamide at 80 8C. The hydroquinone thus formed is continuously reoxidized with the aid of an electrochemical device. Excellent yields for different ketones, aromatic as well as aliphatic and a,b-unsaturated ketones, are obtained. In addition, chemoselectivity towards oxidation of the secondary alcohol is achieved when converting vicinal diols such as 1,2-octanediol and 1,2-decanediol. |
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Wos |
000397584000003 |
Publication Date |
2017-01-26 |
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Edition |
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ISSN |
1615-4150; 1615-4169 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.646 |
Times cited |
4 |
Open Access |
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Notes |
; This work was financially supported by the University of Antwerp (BOF), the Research Foundation – Flanders (FWO) and the Hercules Foundation. ; |
Approved |
Most recent IF: 5.646 |
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Call Number |
UA @ admin @ c:irua:139795 |
Serial |
5559 |
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Author |
Borhani, A.H.; Berghmans, H.; Trashin, S.; De Wael, K.; Fago, A.; Moens, L.; Habibi-Rezaei, M.; Dewilde, S. |
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Title |
Kinetic properties and heme pocket structure of two domains of the polymeric hemoglobin of Artemia in comparison with the native molecule |
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A1 Journal article |
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Year |
2015 |
Publication |
Biochimica et biophysica acta : proteins and proteomics |
Abbreviated Journal |
Bba-Proteins Proteom |
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Volume |
1854 |
Issue |
10a |
Pages |
1307-1316 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
In this project, we studied some physicochemical properties of two different globin domains of the polymeric hemoglobin of the brine shrimp Artemia salina and compared them with those of the native molecule. Two domains (AsHbC1D1 and AsHbC1D5) were cloned and expressed in BL21(DE3)pLysS strain of Escherichiacoli. The recombinant proteins as well as the native hemoglobin (AfHb) were purified from bacteria and frozen Artemia, respectively by standard chromatographic methods and assessed by SDS-PAGE. The heme environment of these proteins was studied by optical spectroscopy and ligand-binding kinetics (e.g. CO association and O2 binding affinity) were measured for the two recombinant proteins and the native hemoglobin. This indicates that the CO association rate for AsHbC1D1 is higher than that of AsHbC1D5 and AfHb, while the calculated P50 value for AsHbC1D1 is lower than that of AsHbC1D5 and AfHb. The geminate and bimolecular rebinding parameters indicate a significant difference between both domains. Moreover, EPR results showed that the heme pocket in AfHb is in a more closed conformation than the heme pocket in myoglobin. Finally, the reduction potential of − 0.13 V versus the standard hydrogen electrode was determined for AfHb by direct electrochemical measurements. It is about 0.06 V higher than the potential of the single domain AsHbC1D5. This work shows that each domain in the hemoglobin of Artemia has different characteristics of ligand binding. |
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Wos |
000362307500008 |
Publication Date |
2015-05-22 |
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Edition |
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ISSN |
1570-9639 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
2.773 |
Times cited |
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Open Access |
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Notes |
; This work was supported by the general grant for visiting scholar of the Ministry of Science, Research and Technology of I. R. Iran and by the University of Antwerp. ; |
Approved |
Most recent IF: 2.773; 2015 IF: 2.747 |
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Call Number |
UA @ admin @ c:irua:125909 |
Serial |
5683 |
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