TY - GEN A1 - Vasjari, Majlinda A1 - Mirsky, Vladimir M. T1 - Calibrated nanoinjections of mercury vapor T2 - Fresenius' Journal of Analytical Chemistry N2 - A simple technique for the calibration of mercury vapor chemosensors is described. It is based on a reductive deposition of a well-defined quantity of mercury (0) onto gold wire followed by thermal evaporation of the mercury into the sensor cell. The quantity of mercury on the gold wire was measured electrochemically by oxidation before and after heating, as well as after storage under different conditions. It is shown that the technique can be used for calibrated injections of nanogram quantities of mercury. The approach was applied to test the performance of ultrasensitive mercury chemoresistors. Y1 - 2000 SN - 1618-2642 SN - 1618-2650 VL - 368 IS - 7 SP - 727 EP - 729 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Wrobel, Nadia A1 - Riepl, Michael A1 - Hirsch, Thomas A1 - Wolfbeis, Otto S. T1 - Intelligente Nanostrukturen für Biosensoren und Sensor-Arrays T2 - BioTec: Zeitschrift für Biotechnologie Y1 - 1999 SN - 0937-2725 VL - 10 SP - 28 EP - 32 ER - TY - CHAP A1 - Wrobel, Nadia A1 - Riepl, Michael A1 - Schinkinger, Manfred A1 - Mirsky, Vladimir M. A1 - Wolfbeis, Otto S. T1 - Capacitive thin film biosensors for bacteriophages and nucleic acids T2 - Proceedings, EMBEC ’99, November 4 - 7, 1999, Vienna, Austria Y1 - 1999 SP - 362 EP - 363 PB - IFMBE CY - Stevenage ER - TY - GEN A1 - Panasyuk-Delaney, Tanya A1 - Mirsky, Vladimir M. A1 - Piletsky, Sergey A. A1 - Wolfbeis, Otto S. T1 - Electropolymerized molecularly imprinted polymers as receptor layers in capacitive chemical sensors T2 - Analytical Chemistry N2 - The first application of molecularly imprinted polymers to chemical sensors with capacitive detection is described. The sensitive layer was prepared by electropolymerization of phenol on gold electrodes in the presence of the template (phenylalanine). The insulating properties of the polymer layer were studied by electrochemical impedance spectroscopy. Electrical leakages through the polymer layer were suppressed by deposition of a self-assembled monolayer of mercaptophenol before polymerization and of alkanethiol after polymerization. At the final stage of sensor preparation, the template was removed. The multilayer system obtained displayed a decrease in electrical capacitance on addition of phenylalanine. Only a low response was observed toward other amino acids and phenol. Y1 - 1999 U6 - https://doi.org/10.1021/ac9903196 SN - 0003-2700 SN - 1520-6882 VL - 71 IS - 20 SP - 4609 EP - 4613 ER - TY - GEN A1 - Hirsch, Thomas A1 - Kettenberger, Hubert A1 - Wolfbeis, Otto S. A1 - Mirsky, Vladimir M. T1 - A simple strategy for preparation of sensor arrays: Nanostructured monolayers as recognition elements T2 - Chemical Communications N2 - The spreader-bar approach is a simple method for producing a huge variety of receptors with different selectivities. A sensor-array consisting of five such receptors is presented. A pattern recognition provides selective detection of different purines and pyrimidines. Y1 - 2003 U6 - https://doi.org/10.1039/b210554c SN - 1359-7345 SN - 1364-548X IS - 3 SP - 432 EP - 433 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Hirsch, Thomas A1 - Panasyuk, Tatiana L. A1 - Piletsky, Sergey A. A1 - Wolfbeis, Otto S. T1 - Two- and three-dimensional artificial chemoreceptors: molecular spreader-bar vs. molecular imprinting T2 - Medical and Biological Engineering and Computing Y1 - 1999 SN - 0140-0118 SN - 1741-0444 VL - 37 IS - suppl.2 SP - 344 EP - 345 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Hirsch, Thomas A1 - Piletsky, Sergey A. A1 - Wolfbeis, Otto S. T1 - A spreader-bar approach to molecular architecture: formation of stable artificial chemoreceptors T2 - Angewandte Chemie International Edition N2 - The destructive influence of lateral diffusion on nanostructured monolayers can be prevented by using the spreader-bar technique. This approach allows the formation of stable artificial receptors for barbituric acid by lateral structuring of a dodecanethiol monolayer with molecular spreader-bars from thiobarbituric acid without chemical polymerization (see schematic representation). The new technique may have applications in chemosensors, affinity chromatography, stereoselective catalysis, and molecular electronics. KW - Molecular architecture KW - Molecular recognition KW - Monolayers KW - Nanostructures KW - Sensors Y1 - 1999 U6 - https://doi.org/10.1002/(SICI)1521-3773(19990419)38:8<1108::AID-ANIE1108>3.0.CO;2-C SN - 1521-3773 VL - 38 IS - 8 SP - 1108 EP - 1110 ER - TY - GEN A1 - Riepl, Michael A1 - Mirsky, Vladimir M. A1 - Wolfbeis, Otto S. T1 - Electrical control of alkanethiols self-assembly on a gold surface as an approach for preparation of microelectrode arrays T2 - Microchimica Acta N2 - It is shown by capacitive monitoring that the self-assembly of alkanethiols on gold electrodes and desorption of these self-assembled monolayers from the electrodes are controlled by the electrode potential. At neutral pH, chemical adsorption of alkanethiols was observed at an electrode potential of +300 mV vs SCE, but only physical adsorption was detected when the electrode potential was −1400 mV vs SCE. At electrode potentials between these values (−300 mV, −600 mV), chemical adsorption of alkanethiols occurred, but the alkanethiol monolayers were not stable in the absence of the alkanethiol in the bulk solution and were desorbed from the gold electrode. The desorption rate was higher at more negative electrode potentials. These results can be used in designing methods for electrically addressable immobilization of different receptors on (micro)electrode arrays. This has been demonstrated by deposition of two different types of alkanethiols onto a two-electrode array. KW - self-assembly KW - electrical control KW - electrode capacitance KW - addressable immobilization KW - (bio)sensor array Y1 - 1999 U6 - https://doi.org/10.1007/s006040050006 SN - 0026-3672 SN - 1436-5073 VL - 131 IS - 1 SP - 29 EP - 34 ER - TY - GEN A1 - Schweiß, Rüdiger A1 - Mirsky, Vladimir M. A1 - Wolfbeis, Otto S. T1 - Capacitive study of self-assembled alkylthiol monolayers: surface charge effects and kinetics of surfactants adsorption T2 - Materials Science Forum Y1 - 1998 U6 - https://doi.org/10.4028/www.scientific.net/MSF.287-288.427 SN - 1662-9752 SN - 0255-5476 VL - 287-288 SP - 427 EP - 430 ER - TY - GEN A1 - Ando, Masanori A1 - Swart, Claudia A1 - Pringsheim, Erika A1 - Mirsky, Vladimir M. A1 - Wolfbeis, Otto S. T1 - Optical ozone detection by use of polyaniline film T2 - Solid State Ionics N2 - We report on the optical ozone sensitivity of a polyaniline (PANI) film prepared on the inner wall of a polystyrene cuvette by chemical oxidation of aniline from aqueous solution. The PANI film showed changes of optical absorbance in the presence of 50–100 ppm ozone in air at room temperature. The absorbance change was largest at wavelengths in the range of 500–800 nm. The absorbance changes brought about by ozone was partially reversible after removal of ozone from the atmosphere. These results suggest that PANI is a potential material for optical ozone detection. KW - Optical ozone detection KW - Polyaniline film KW - Visible near-IR absorption Y1 - 2002 U6 - https://doi.org/10.1016/S0167-2738(02)00338-7 SN - 0167-2738 VL - 152-153 SP - 819 EP - 822 ER - TY - GEN A1 - Mirsky, Vladimir M. T1 - New applications of self-assembled monolayers (Invited review) T2 - Trends in Analytical Chemistry N2 - New applications of self-assembled monolayers of thiol compounds on gold electrodes are reviewed. They include: (i) exploitation of electrical control of self-assembly of thiol compounds for electrically- addressable immobilization of receptor molecules onto sensor arrays; (ii) a spreader-bar technique for formation of stable nanostructures; and, (iii) use of self-assembled monolayers as selective filters for chemical sensors. Y1 - 2002 U6 - https://doi.org/10.1016/S0165-9936(02)00601-5 SN - 0165-9936 VL - 21 IS - 6-7 SP - 439 EP - 450 ER - TY - GEN A1 - Wrobel, Nadia A1 - Schinkinger, Manfred A1 - Mirsky, Vladimir M. T1 - A novel ultraviolet assay for testing side reactions of carbodiimides T2 - Analytical Biochemistry N2 - Carbodiimides possess considerable absorbance in the ultraviolet region; the extinction coefficient of 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC) in water is ϵ214 = 6.3 · 103 L mol−1 cm−1. It provides a very simple method for testing possible side reactions of carbodiimides. This technique was used to study effects of pH, different buffers, and other components typically present in biological samples on EDC stability. It was shown that the hydrolysis rate in pure water increased from 1.5 · 10−5 to 5 · 10−4 s−1 by pH decreasing from 7 to 4. A strong increase of the rate of EDC loss was observed in the presence of different components. This effect can be described by the following row of hydrolysis rates: citrate ⪢ acetate ≈ phosphate ⪢ SDS. The results can be used to optimize carbodiimide-mediated reactions of peptide bond formation in organic chemistry or peptide synthesis or during immobilization or cross-linking of biological molecules. Y1 - 2002 U6 - https://doi.org/10.1006/abio.2002.5646 SN - 0003-2697 VL - 305 IS - 2 SP - 135 EP - 138 ER - TY - GEN A1 - Panasyuk-Delaney, Tanya A1 - Mirsky, Vladimir M. A1 - Wolfbeis, Otto S. T1 - Capacitive creatinine sensor based on molecularly imprinted polymer T2 - Electroanalysis N2 - The first reversible chemosensor to creatinine based on artificial chemoreceptors is described. The receptor layer was prepared by molecularly imprinted photopolymerization of acrylamidomethylpropanesulfonic acid and methylenediacrylamide. The polymer layer was grafted onto the surface of gold electrodes coated with an alkanethiol monolayer. Creatinine binding was detected by a decrease in the electrode capacitance. The sensor response is reversible and highly selective: no response to addition of sodium chloride, creatine, urea or glucose were observed. The detection limit for creatinine is 10 μM which is optimal for medical applications. KW - Capacitive sensor KW - Creatinine KW - Molecularly imprinted polymer KW - Chemical sensor KW - Photografted polymerization Y1 - 2002 U6 - https://doi.org/10.1002/1521-4109(200202)14:3<221::AID-ELAN221>3.0.CO;2-Y SN - 1521-4109 VL - 14 IS - 3 SP - 221 EP - 224 ER - TY - GEN A1 - Mirsky, Vladimir M. T1 - Affinity sensors in non-equilibrium conditions: a highly selective chemosensing by means of low selective chemosensors T2 - Sensors N2 - The selectivity of measurements by means of affinity sensors in (quasi)equilibrium conditions and in non-equilibrium conditions was compared. The results show that the measurements in non-equilibrium conditions can reduce or even eliminate a relative contribution of interferents to a sensor signal. KW - affinity sensors KW - kinetics KW - selectivity Y1 - 2001 U6 - https://doi.org/10.3390/s10100013 SN - 1424-8220 VL - 1 IS - 1 SP - 13 EP - 17 ER - TY - CHAP A1 - Wu, Meng A1 - Lin, Zhihong A1 - Mirsky, Vladimir M. A1 - Wolfbeis, Otto S. ED - Zhou, Yikai T1 - Detection of DNA hybridization with surface plasmon resonance biosensor: comparison of immobilization of oligonucleotides by ssDNA and dsDNA T2 - Proceedings, International Conference on Sensor Technology (ISTC 2001), 10 - 12 October 2001, Wuhan, China N2 - In this research, a surface-plasmon resonance biosensor for nucleic acid detection was constructed, optimized and characterized. The kinetic response on hybridization was also studied. The biosensor was use as a platform for the study of the surface coverage control by single-strand or double-strand oligonucleotide immobilization. The dsDNA immobilization and offers a new way to surface coverage control for the nucleic acid biosensor construction. Y1 - 2001 SN - 0-8194-4119-8 U6 - https://doi.org/10.1117/12.440180 SP - 23 EP - 26 PB - SPIE CY - Bellingham, Wash. ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Panasyuk-Delaney, Tanya A1 - Wolfbeis, Otto S. T1 - Chemical sensors based on ultrathin membranes from molecularly imprinted polymers T2 - Membrane & cell biology Y1 - 2001 VL - 18 IS - 6 SP - 496 EP - 501 ER - TY - CHAP A1 - Lin, Zhihong A1 - Wu, Meng A1 - Ren, Shu A1 - Arbter, Michaela A1 - Boehmer, Martin A1 - Mirsky, Vladimir M. A1 - Wolfbeis, Otto S. ED - Zhou, Yikai T1 - Study of single and dual NIR fluorescently labeled nucleic acid conjugates for nucleic acid detection T2 - Proceedings, International Conference on Sensor Technology (ISTC 2001), 10 - 12 October 2001, Wuhan, China N2 - In this research, a near-IR fluorescent labeled nucleic acid conjugate for the nucleic acid detection was synthesized, and characterized preliminarily for the detection of the nucleic acid. Th conjugate combines the molecular recognition properties of the oligonucleotides with the near-IR fluorescence label PR646. Both single- and dual- labeled conjugates were studied for their hybridization with the complementary nucleic acid. The dual labeled conjugate has indicated that the self-quenching effect exists in ssDNA form while the fluorescence increases greatly after hybridization with the complementary nucleic acids. The time-resolved fluorescence was also studied. KW - Near infrared KW - luminescence Y1 - 2001 SN - 0-8194-4119-8 U6 - https://doi.org/10.1117/12.440165 SP - 111 EP - 114 PB - SPIE CY - Bellingham, Wash. ER - TY - CHAP A1 - Mirsky, Vladimir M. A1 - Riepl, Michael A1 - Mass, Markus A1 - Hirsch, T. A1 - Schweiss, R. A1 - Wolfbeis, Otto S. ED - Vincenzini, Pietro ED - Dori, L. T1 - Capacitive detection of analyte binding in thin film chemo- and biosensors T2 - Solid State Chemical and Biochemical Sensors Y1 - 1999 SN - 88-86538-27-8 SP - 441 EP - 448 PB - Techna CY - Faenza ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Mass, Markus A1 - Krause, Christian A1 - Wolfbeis, Otto S. T1 - Capacitive approach to determine phospholipase A2 activity towards artificial and natural substrates T2 - Analytical Chemistry N2 - A capacitive approach has been employed to develop a novel method to determine phospholipase activity. The sensing electrodes have a structure like Au/S(CH₂)₁₇CH₃/substrate/electrolyte. Hydrolysis of the substrate, mediated by phospholipase A₂, leads to the formation of water-soluble products from the insoluble substrate. This results in desorption of these products into aqueous phase and corresponding increase of the electrode capacitance. The requirement of high water solubility of the reaction products can be achieved in two ways. In the first, short-chain phospholipids are used as the substrate, in which case, water-soluble products are formed and no additional reagents are required to promote desorption of these products. The sensors prepared by this strategy provide sensitive qualitative detection of phospholipases. The second way is based on the use of a water-soluble acceptor (for example, β-cyclodextrin) to solubilize the products of hydrolysis. It allows semiquantitative detection of phospholipase activity toward long-chain natural substrates. The reaction kinetics for this case was found to be monoexponential and linearly dependent on the phospholipase concentration. The detection limit of this method, as tested with phospholipase A₂ from bee venom and soy bean lecithin as the substrate, is ∼0.5 ng/mL (500 μunits/mL). Y1 - 1998 U6 - https://doi.org/10.1021/ac980102w SN - 0003-2700 SN - 1520-6882 VL - 70 IS - 17 SP - 3674 EP - 3678 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Riepl, Michael A1 - Wolfbeis, Otto S. T1 - Capacitive monitoring of protein immobilization and antigen-antibody reaction on the monomolecular films of alkylthiols adsorbed on gold electrodes T2 - Biosensors and Bioelectronics N2 - Self-assembled monolayers of omega-mercaptohexadecanoic acid and omega-mercaptohexadecylamine on gold electrodes are stable at neutral pH and display pure capacitive behavior at frequencies around 20 Hz. Different methods of covalent immobilization of proteins on these monolayers are compared. Various reagents including succinimides, thionylchloride, p-nitrophenol and carbodiimides were used to activate the carboxy groups of the adsorbed monolayer of omega-mercaptohexadecanoic acid. Glutaraldehyde, cyanuric chloride and phenylene diisocyanate were used to activate the amino groups of the monolayer of omega-mercaptohexadecylamine. The immobilization of albumin on the activated surface was studied by capacitive measurements. The N-hydroxysuccinimide and carbodiimide methods were identified as most suitable for protein immobilization in that they did not compromise the insulating properties of the alkylthiol layer and led to maximal increase of its dielectric thickness. These approaches were used for a layer-by-layer preparation of a capacitive immunosensor. Specifically, antibodies to human serum albumin were immobilized on the alkylthiol mono-layer. Binding of the antigen led to a decrease of the electrode capacitance. The detection limit of the immunosensor is as low as 15 nM (1 mg/l). Y1 - 1997 U6 - https://doi.org/10.1016/S0956-5663(97)00053-5 SN - 0956-5663 VL - 12 IS - 9-10 SP - 977 EP - 989 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Krause, Christian A1 - Heckmann, Klaus Dietrich T1 - Capacitive detection of adsorption/desorption on hydrophobized gold electrodes: an application for surfactants adsorption and phospholipase assay T2 - Chimica Chronica, New Series Y1 - 1996 VL - 25 SP - 179 EP - 194 ER - TY - GEN A1 - Krause, Christian A1 - Mirsky, Vladimir M. A1 - Heckmann, Klaus Dietrich T1 - Capacitive detection of surfactant adsorption on hydrophobized gold electrodes T2 - Langmuir N2 - Nonspecific adsorption of surfactants on polycrystalline gold electrodes, covered by a chemically adsorbed monomolecular layer of octadecanethiol, was studied by means of capacitive measurements. Homologous series of fatty acids (from decane to tetradecane acids) and dodecanepyridinium chloride were used as surfactants. The behavior of the electrode was completely different in the first and subsequent cycles of adsorption/desorption. In the first adsorption cycle, an initial capacitance jump at low concentrations (<10 μM) occurs, while later the curves show the usual saturation behavior. The first surfactant layer could not be completely desorbed; only the electrode capacitance shown after the jump was reached. Subsequent cycles do not reveal any capacitance jumps and were completely reversible. Adsorption curves in the series of monoalkyl acids are shifted according to the Traube rule. A comparison with the surfactant adsorption at the air/water interface has been done. Y1 - 1996 U6 - https://doi.org/10.1021/la9601869 SN - 0743-7463 VL - 12 IS - 25 SP - 6059 EP - 6064 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Krause, Christian A1 - Heckmann, Klaus Dietrich T1 - Capacitive sensor for lipolytic enzymes T2 - Thin Solid Films N2 - The preparation of the capacitive biosensor for monitoring the activity of enzymes (lipases, phospholipases, etc.) hydrolysing waterinsoluble substrates into water-soluble products is described. The sensor is based on a sandwich-like structure: Au/S(CH₂)₁₇CH₁/substrate/electrolyte. Hydrolysis of the substrate leads to the formation of water-soluble products and desorption of these compounds from the electrode. When the product formation is the rate-limiting step of this process, the desorption rate is determined by the enzyme activity. The desorption can be easily monitored as an increase of the electrode capacitance. By following this principle it was possible to develop a sensor monitoring phospholipase A₂ activity even at the 50 pg ml-1 level. KW - Phospholipase AZ KW - Enzyme assay KW - Capacitive sensor KW - Self-assembly layer Y1 - 1996 U6 - https://doi.org/10.1016/S0040-6090(95)08485-1 SN - 0040-6090 VL - 284-285 SP - 939 EP - 941 ER - TY - GEN A1 - Hayessen, R. A1 - Mirsky, Vladimir M. A1 - Heckmann, Klaus Dietrich T1 - Anion-sensitive properties of alkylguanidines in the membrane electrodes and monomolecular layers T2 - Sensors and Actuators B: Chemical N2 - Water-insoluble alkylguanidines and cycloguanidines (triphenyl-, tricyclohexyl- and tribenzylguanidines) have been synthesized and studied as potential nitrate ligands. Anion-dependent expansion of dialkylguanidinium monolayers at the water/air interface is observed; the area per guanidinium molecule in the monolayer increases according to the series I−>NO3−>Cl−. Membranes for nitrate-sensitive electrodes are prepared by immobilization of alkyl- and cycloguanidiniums into a plasticized polyvinylchloride matrix. Nernst-type dependence of the electrode potential on the nitrate concentration is observed for the electrodes prepared with long-chain alkylguanidines, and only a small response is observed for electrodes based on the cycloguanidines. The selectivity qualitatively follows the Hofmeister series: I−>NO3−>Br−>F−. The effect of plasticizers on the dielectric constant of the membranes has been studied, and variations from 6.5 (dibutylphthalate) to 16 (tributylphosphate) are obtained. In spite of some quantitative variations of the electrode selectivity, the Hofmeister series is qualitatively valid for all the electrodes. No correlation between dielectric constant of the electrode membrane and electrode selectivity is observed. KW - Alklyguanidines KW - Anion selectivity KW - Cycloguanidines KW - Membrane electrodes KW - Monomolecular layers Y1 - 1996 U6 - https://doi.org/10.1016/S0925-4005(97)80032-9 SN - 0925-4005 VL - 32 IS - 3 SP - 215 EP - 220 ER - TY - GEN A1 - Mirsky, Vladimir M. T1 - Fatty acids effect on the phospholipase A: electrostatical mechanism of activation T2 - Membrane and Cell Biology Y1 - 1995 SN - 1023-6597 VL - 9 SP - 175 EP - 184 ER - TY - CHAP A1 - Hayessen, R. A1 - Mirsky, Vladimir M. A1 - Heckmann, Klaus Dietrich T1 - Alkylguanidines as a base for nitrate ion sensors T2 - Sensor-95, Kongress-Band, 7. Internationale Fachmesse mit Kongreß für Sensoren, Meßaufnehmer & Systeme, 9. - 11. Mai, Nürnberg Y1 - 1995 SP - 841 EP - 844 PB - ACS CY - Wunstorf-Steinhude ER - TY - GEN A1 - Mirsky, Vladimir M. T1 - An effect of the lipid hydrolysis products on the phospholipase A₂ action towards lipid monolayer T2 - Physics and Chemistry of Lipids N2 - The effect of lauric acid (LA) and lysolauroyllecithin (LLL) on the hydrolysis of lipid in monolayer by phospholipase A₂ from Bee venom was studied. It was found that LLL inhibits phospholipase action under both high (39 mN/m) and low (25 mN/m) surface pressure. On the other hand, LA inhibits phospholipase action under the low surface pressure (15 mN/m or 25 mN/m), but increases enzyme activity under high surface pressure (39 mN/m). This activating effect can be suppressed by high ionic strength of the aqueous subphase. It is suggested that an increase of the negative surface charge of the lipid monolayer, followed by an increase of the local concentrations of the positively charged enzyme and calcium near the monolayer is a coupling factor between fatty acid accumulation and phospholipase activation. Such an autocatalytic process can only occur when the substrate is organised into monolayer, bilayer or micelles, therefore it can be considered as a reason for the substrate activation and induction time before lipid hydrolysis. Y1 - 1994 SN - 0009-3084 VL - 70 IS - 1 SP - 75 EP - 81 ER - TY - GEN A1 - Stozhkova, I. N. A1 - Mirsky, Vladimir M. A1 - Sokolov, Valeri S. T1 - Stoichiometry of the photochemical reaction leading to the damage of BLM in the presence of hematoporphyrin T2 - Biological membranes Y1 - 1993 VL - 10 IS - 1 SP - 44 EP - 49 ER - TY - GEN A1 - Stozhkova, I. N. A1 - Mirsky, Vladimir M. A1 - Kayushina, R. L. A1 - Erokhin, V. V. A1 - Mironov, A. F. T1 - An interaction of hematoporphyrin dimethylether with model lipid membranes T2 - Biological membranes Y1 - 1992 VL - 9 IS - 1 SP - 74 EP - 79 ER - TY - GEN A1 - Stozhkova, I. N. A1 - Mirsky, Vladimir M. A1 - Szito, T. T1 - Photosensitized by hematoporphyrin dimethylether damage of bilayer lipid membrane T2 - Biological membranes Y1 - 1991 SN - 0748-8653 VL - 8 IS - 4 SP - 412 EP - 418 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Stozhkova, I. N. A1 - Szito, T. T1 - Photosensitized damage of bilayer lipid membrane in the presence of hematoporphyrin dimethylether T2 - Journal of Photochemistry and Photobiology. B, Biology N2 - The variations in electrical conductivity and surface tension of planar bilayer lipid membranes (BLMs) sensitized by a haematoporphyrin dimethylether (HpDME) on visible light irradiation are reported. The irradiation of BLMs immediately leads to a decrease in membrane surface tension. On irradiation the conductivity of BLMs remains constant for a certain period of time (induction time), followed by an increase, terminated by membrane breakage. The induction time is not dependent on stirring of the solution, the addition of azide or ferricyanide to the solution, the addition of antioxidant to the lipid or substitution of air for argon in the cell. The induction time decreases for repeated irradiations or for any new BLM formed in the same cell immediately after the previous membrane has been broken. The conductivity shift consists of reversible and irreversible components. These results suggest that the irradiation of BLMs sensitized by HpDME leads to an accumulation of photoproducts in the membrane which induce pore formation and to a decrease in BLM stability when the concentration of the photoproducts exceeds a critical level. Y1 - 1991 SN - 1011-1344 VL - 8 IS - 3 SP - 315 EP - 324 ER - TY - GEN A1 - Portnov, V. I. A1 - Mirsky, Vladimir M. A1 - Markin, Vladislav S. T1 - Bacteriorhodopsin: current-voltage dependence T2 - Bioelectrochemistry and Bioenergetics N2 - Current-voltage dependences for different tentative bacteriorhodopsin models were studied in order to explain the linearity of this dependence observed in our previous experiments. It is proved that the best correspondence with experiment occurs when the passive proton transport path is assumed to contain many binding sites and the thickness of the widest barrier separating these sites is not more than 1 nm. One of the following two conditions is necessary: (1) electrostatic repulsion of protons in the channel is so strong that not more than one proton can be in the channel at a time; the potential energy of a proton in this channel decreases linearly towards the active site. (2) Electrostatic repulsion between protons in the channel is moderate, and the binding energy of a proton at all channel sites is equal. Under conditions of high channel occupation, single-file effects lead to non-linearity of the current-voltage characteristics if there is no electrostatic repulsion. Y1 - 1990 SN - 0302-4598 VL - 23 IS - 1 SP - 45 EP - 63 ER - TY - GEN A1 - Stozhkova, I. N. A1 - Mirsky, Vladimir M. T1 - Simulation of photoradiation therapy: photosensitized effect of hematoporphyrin dimethylether on planar bilayer lipid membrane T2 - Bulletin of Experimental Biology and Medicine Y1 - 1990 SN - 0007-4888 SN - 1573-8221 VL - 110 IS - 1 SP - 898 EP - 900 ER - TY - GEN A1 - Sokolov, Valeri S. A1 - Mirsky, Vladimir M. A1 - Toth-Boconadi, R. A1 - Markin, Vladislav S. A1 - Kesthelyi, L. T1 - Bacteriorhodopsin photocycle in decane T2 - Biological membranes Y1 - 1988 SN - 0233-4755 VL - 5 SP - 595 EP - 599 ER - TY - GEN A1 - Portnov, V. I. A1 - Mirsky, Vladimir M. A1 - Markin, Vladislav S. T1 - Current-voltage characteristic of bacteriorhodopsin T2 - Biological membranes Y1 - 1988 SN - 0233-4755 VL - 5 SP - 198 EP - 216 ER - TY - CHAP A1 - Markin, Vladislav S. A1 - Mirsky, Vladimir M. A1 - Chizmadzhev, Y. A. ED - Ovchinnikov, Yurij A. ED - Hucho, F. T1 - Photoelectrical activity of bacteriorhodopsin in planar lipid bilayer T2 - Receptors and Ion Channels, proceedings of the Symposium on Receptors and Ion Channels, Tashkent, USSR, Oct. 2 - 5, 1986 Y1 - 1987 SN - 3-11-010346-X SP - 247 EP - 254 PB - de Gruyter CY - Berlin [u.a.] ER - TY - GEN A1 - Sokolov, Valeri S. A1 - Mirsky, Vladimir M. A1 - Markin, Vladislav S. A1 - Kazarinov, V. E. T1 - Automatization of bioelectrochemical experiment T2 - Soviet electrochemistry Y1 - 1986 VL - 22 SP - 959 EP - 966 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Sokolov, Valeri S. A1 - Markin, Vladislav S. A1 - Chekulaeva, L. N. T1 - Bilayer lipid membrane formation from bacteriorhodopsin suspension in lipid solution T2 - Biological membranes Y1 - 1984 SN - 0233-4755 VL - 1 SP - 1143 EP - 1150 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Sokolov, Valeri S. A1 - Markin, Vladislav S. T1 - Reconstitution of bacteriorhodopsin in bilayer lipid membrane by monolayer method T2 - Soviet electrochemistry Y1 - 1984 VL - 20 SP - 876 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Sokolov, Valeri S. A1 - Melnik, E. I. A1 - Diukova, T. V. T1 - A study of incorporation of bacteriorhodopsin into bimolecular lipid membranes T2 - Biophysics Y1 - 1984 SN - 0006-3029 VL - 29 SP - 250 EP - 253 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Sokolov, Valeri S. T1 - Criteria of bacteriorhodopsin incorporation into bimolecular lipid membrane T2 - Biophysics Y1 - 1984 SN - 0006-3029 VL - 29 SP - 246 EP - 249 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Sokolov, Valeri S. A1 - Diukova, T. V. A1 - Melnik, E. I. T1 - A study of bacteriorhodopsin-containing proteoliposome incorporation into bimolecular lipid membranes T2 - Bioelectrochemistry and Bioenergetics N2 - The photoresponses of planar bimolecular lipid membranes (BLM) modified with liposomes containing bacteriorhodopsin (BR) were investigated in the presence of Ca 2+ cations. Short-circuit currents during switch-on and switch-off of the light were measured within a time scale exceeding the BR photocycle, and the dependence of the currents on external field and membrane conductance was studied. A comparison of the experimental data with computed values indicates that the photoresponses observed are due not only to BR contained in the proteoliposomes adhered to the BLM, as generally believed, but also to BR in BLM itself. The transfer of BR to BLM may result from the complete fusion of liposomes with the planar membrane. The existence of such a transfer is indicative of the possibility of obtaining the most convenient model system for BR studies: a planar bimolecular lipid membrane containing incorporated BR. Y1 - 1983 SN - 0302-4598 VL - 11 IS - 4-6 SP - 327 EP - 346 ER - TY - GEN A1 - Efremenko, Yulia A1 - Mirsky, Vladimir M. T1 - Virtual sensor array consisting of a single sensor element with variable affinity: an application for analysis of fish freshness T2 - Sensors and Actuators B: Chemical N2 - Recently reported concept of electrical control of sensor affinity was applied for formation of a virtual sensor array based on the single sensing element. Affinity properties of this element were modulated by electrically controlled conversion of chemosensitive material between its different redox states possessing different affinity. The sensor was realized on the basis of electrochemical chemotransistor in which a low temperature ionic liquid containing chloride was used to connect the chemosensitive material to the Ag/AgCl reference electrode. The concept of virtual array was proved by its application for monitoring of fish headspace. Using three characteristics of the sensor response measured at three different redox states of the same sensor material, we have obtained signals from a virtual sensor array consisting of nine chemosensitive elements. The sensor displays systematic changes of its nine signals during fish degradation and allows us to make quantitative analysis of its freshness defined as the after the catch. The level of detection is far below the level of organoleptic detection. KW - Chemical sensor KW - Sensor arrays KW - Affinity KW - Chemotransistor KW - Conductometric sensor KW - Conducting polymer KW - Fish freshness Y1 - 2017 U6 - https://doi.org/10.1016/j.snb.2016.10.126 SN - 0925-4005 VL - 241 SP - 652 EP - 657 ER - TY - GEN A1 - Nizamov, Shavkat A1 - Scherbahn, Vitali A1 - Mirsky, Vladimir M. T1 - Ionic referencing in surface plasmon microscopy: visualization of the difference in surface properties of patterned monomolecular layers T2 - Analytical Chemistry N2 - An approach for visualization of patterned monomolecular layers in surface plasmon microscopy (SPM) is suggested. The development of hidden image in SPM is achieved by referencing of images obtained in the presence of electrolytes with a high molar refraction of either anions or cations. A formation of diffuse layer near the charged surface areas leads to the redistribution of ions. The ratio of SPM images allows one to visualize this redistribution and to distinguish surface areas with different properties. The approach is unobtrusive and robust; it can be used with most SPR imaging instruments. Y1 - 2017 U6 - https://doi.org/10.1021/acs.analchem.7b00251 SN - 0003-2700 SN - 1520-6882 VL - 89 IS - 7 SP - 3873 EP - 3878 ER - TY - CHAP A1 - Nizamov, Shavkat A1 - Scherbahn, Vitali A1 - Mirsky, Vladimir M. T1 - Advanced wide-field surface plasmon microscopy of single adsorbing nanoparticles T2 - Optical Sensors 2017, 24–27 April 2017 Prague, Czech Republic N2 - In-situ detection and characterization of nanoparticles in biological media as well as in food or other complex samples is still a big challenge for existing analytical methods. Here we describe a label-free and cost-effective analytical method for detection of nanoparticles in the concentration range 106 -1010 NPs/ml. The proposed method is based on the surface plasmon resonance microscopy (SPRM) with a large field of view (~1.3mm2 ). It is able to detect and count adsorbing nanoparticles individually, totally up to the hundreds of thousands of NPs on the sensor surface. At constant diffusion conditions the detection rate is proportional to the number concentration of NPs, this provides an approach to determine the NPs concentration. The adsorption of nanoparticle can be manipulated by the surface functionalization, pH and electrolyte concentration of suspensions. Images of detected nanoparticles can be quantified in order to characterize them individually. The image intensity grows quasi-linearly with nanoparticle size for the given material. However, the size and material of nanoparticle cannot be resolved directly from the image. For determination of chemical composition, SPRM can be assisted by electrochemical analysis. In this case, the gold sensor surface is used both as a resonant media for plasmon microscopy and as a working electrode. Under potential sweep, the adsorbed NPs can be subjected to electrochemical dissolution, which is detected optically. The potential of this conversion characterizes the material of NPs. Y1 - 2017 SN - 978-1-5106-0963-1 SN - 978-1-5106-0964-8 U6 - https://doi.org/10.1117/12.2267144 PB - SPIE CY - Bellingham, Washington ER - TY - CHAP A1 - Nizamov, Shavkat A1 - Scherbahn, Vitali A1 - Mirsky, Vladimir M. T1 - Wide-field surface plasmon microscopy of nano- and microparticles: features, benchmarking, limitations, and bioanalytical applications T2 - Optical Sensors 2017, 24-27 April 2017, Prague, Czech Republic N2 - Detection of nano- and micro-particles is an important task for chemical analytics, food industry, biotechnology, environmental monitoring and many other fields of science and industry. For this purpose, a method based on the detection and analysis of minute signals in surface plasmon resonance images due to adsorption of single nanopartciles was developed. This new technology allows one a real-time detection of interaction of single nano- and micro-particles with sensor surface. Adsorption of each nanoparticle leads to characteristic diffraction image whose intensity depends on the size and chemical composition of the particle. The adsorption rate characterizes volume concentration of nano- and micro-particles. Large monitored surface area of sensor enables a high dynamic range of counting and to a correspondingly high dynamic range in concentration scale. Depending on the type of particles and experimental conditions, the detection limit for aqueous samples can be below 1000 particles per microliter. For application of method in complex media, nanoparticle images are discriminated from image perturbations due to matrix components. First, the characteristic SPRM images of nanoparticles (templates) are collected in aqueous suspensions or spiked real samples. Then, the detection of nanoparticles in complex media using template matching is performed. The detection of various NPs in consumer products like cosmetics, mineral water, juices, and wines was shown at sub-ppb level. The method can be applied for ultrasensitive detection and analysis of nano- and micro-particles of biological (bacteria, viruses, endosomes), biotechnological (liposomes, protein nanoparticles for drug delivery) or technical origin. Y1 - 2017 SN - 978-1-5106-0963-1 SN - 978-1-5106-0964-8 U6 - https://doi.org/10.1117/12.2267158 PB - SPIE CY - Bellingham, Washington, USA ER - TY - GEN A1 - Laurinavichyute, Veronika K. A1 - Nizamov, Shavkat A1 - Mirsky, Vladimir M. T1 - The Role of Anion Adsorption in the Effect of Electrode Potential on Surface Plasmon Resonance Response T2 - ChemPhysChem : a European journal of physical chemistry and chemical physics N2 - Surface plasmon resonance, being widely used in bioanalytics and biotechnology, is influenced by the electrical potential of the resonant gold layer. To evaluate the mechanism of this effect, we have studied it in solutions of various inorganic electrolytes. The magnitude of the effect decreases according to the series: KBr>KCl>KF>NaClO4. The data were treated by using different models of the interface. A quantitative description was obtained for the model, which takes into account the local dielectric function of gold being affected by the free electron charge, diffuse ionic layer near the gold/water interface, and specific adsorption of halides to the gold surface with partial charge transfer. Taking into account that most biological experiments are performed in chloride-containing solutions, detailed analysis of the model at these conditions was performed. The results indicate that the chloride adsorption is the main mechanism for the influence of potential on the surface plasmon resonance. The dependencies of surface concentration and residual charge of chloride on the applied potential were determined. Y1 - 2017 U6 - https://doi.org/10.1002/cphc.201601288 SN - 1439-7641 SN - 1439-4235 VL - 18 IS - 12 SP - 1552 EP - 1560 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Rödiger, Stefan A1 - Schierack, Peter A1 - Roggenbuck, Dirk T1 - Preface to the Special Issue on PCR on chip and related technologies T2 - Microchimica Acta Y1 - 2014 U6 - https://doi.org/10.1007/s00604-014-1246-1 VL - 181 IS - 13/14 SP - 1609 EP - 1610 ER - TY - CHAP A1 - Scherbahn, Vitali A1 - Nizamov, Shavkat A1 - Mirsky, Vladimir M. ED - Schöning, Michael J. ED - Poghossian, Arshak T1 - Toward ultrasensitive surface plasmon resonance sensors T2 - Label-free biosensing : advanced materials, devices and applications N2 - Despite the history of application of surface plasmon resonance (SPR) for chemo- and biosensing being over 30 years long, the development of this technique is still in progress. This review is focused on the technological aspects of further improvement of analytical performance of SPR transducers based on Kretschmann configuration. We describe basic measurement configurations, their improvements and optimizations, and their drawbacks and limitations. An importance of referencing in SPR sensors is highlighted. The referencing approaches are classified into the following domains: (1) macroscopic spatially separated referencing, (2) self-referencing based on micro-patterning, (3) in-place referencing, (4) spatiotemporal referencing, and (5) electrochemically assisted referencing. The underlying principles of these approaches, examples of their implementation, and resulting improvements of sensor performance are described. Finally, an analysis of SPR data and an extraction of affinity properties are discussed. KW - Self-referencing KW - Surface plasmon resonance KW - Surface plasmon resonance microscopy Y1 - 2018 SN - 978-3-319-75220-4 SN - 978-3-319-75219-8 U6 - https://doi.org/https://doi.org/10.1007/5346_2017_21 SP - 409 EP - 448 PB - Springer CY - Cham ER - TY - GEN A1 - Gutic, Sanjin J. A1 - Kozlica, Dzevad K. A1 - Bajuk-Bogdanovic, Danica A1 - Mitric, Miodrag A1 - Mirsky, Vladimir M. A1 - Mentus, Slavko V. A1 - Pasti, Igor A. T1 - Electrochemical tuning of capacitive response of graphene oxide T2 - Physical Chemistry, Chemical Physics N2 - The increasing energy demands of modern society require a deep understanding of the properties of energy storage materials, as well as the tuning of their performance. We show that the capacitance of graphene oxide (GO) can be precisely tuned using a simple electrochemical reduction route. In situ resistance measurements, in combination with cyclic voltammetry measurements and Raman spectroscopy, have shown that upon reduction GO is irreversibly deoxygenated, which is further accompanied by structural ordering and an increase in electrical conductivity. The capacitance is maximized when the concentration of oxygen functional groups is properly balanced with the conductivity. Any further reduction and deoxygenation leads to a gradual loss of capacitance. The observed trend is independent of the preparation route and the exact chemical and structural properties of GO. It is proposed that an improvement in the capacitive properties of any GO can be achieved by optimization of its reduction conditions. Y1 - 2018 U6 - https://doi.org/10.1039/C8CP03631D SN - 1463-9084 SN - 1463-9076 VL - 35 IS - 20 SP - 22698 EP - 22709 ER - TY - GEN A1 - Hammami, Asma A1 - Raouafi, Noureddine A1 - Mirsky, Vladimir M. T1 - Electrically controlled Michael addition: Addressing of covalent immobilization of biological receptors T2 - Biosensors and Bioelectronics N2 - Electrically addressed covalent immobilization of biomolecules to the defined electrodes of an electrode array is described. It is based on Michael addition of the thiol group of biomolecules to α,β-unsaturated carbonyl groups of benzoquinone. This “click” reaction was tested by immobilization of a number of thiolated compounds on the simplest array consisting of two gold electrodes coated by a self-assembled monolayer of benzoquinone-terminated hexanethiol. Electrically controlled binding of hexanethiol, ferrocenylhexanethiol, human serum albumin and thiol-terminated single-stranded DNA (ssDNA) was investigated. The binding was studied using cyclic voltammetry, X-ray photoelectron spectroscopy and surface plasmon resonance. The reaction requires the oxidized state of the benzoquinone moiety; this can be reached by applying of a moderate anodic potential to the electrode. Surface plasmon resonance measurements demonstrated that the thiol-modified ssDNA immobilized by this technique binds complementary synthetic oligonucleotides or PCR-amplified DNA fragments. The developed technology of electrical addressing of covalent immobilization can be applied for fabrication of sensor arrays. KW - Self-assembled monolayer Immobilization of biomolecules Addressable immobilization Michael addition Cyclic voltammetry Surface plasmon resonance Y1 - 2018 U6 - https://doi.org/10.1016/j.bios.2018.08.044 SN - 1873-4235 SN - 0956-5663 VL - 121 SP - 72 EP - 79 ER - TY - GEN A1 - Tonder, Karin A1 - Nizamov, Shavkat A1 - Scherbahn, Vitali A1 - Mirsky, Vladimir M. T1 - Das Unsichtbare im Blick Ultrasensitive Detektion, Quantifizierung und Identifizierung industriell erzeugter und biologischer Nanopartikel T2 - Laborpraxis Y1 - 2018 UR - https://files.vogel.de/vogelonline/vogelonline/issues/lp/8263.pdf SN - 0344-1733 VL - 42 IS - 1 SP - 24 EP - 26 ER - TY - GEN A1 - Mirsky, Vladimir M. T1 - Nanodetector: Ultrasensitive plasmonic detection of single nanoparticles T2 - Compendium of Projects in the European Nanosafety Cluster Y1 - 2012 UR - https://www.nanosafetycluster.eu/home/european-nanosafety-cluster-compendium.html VL - 2012 SP - 79 EP - 83 ER - TY - GEN A1 - Mirsky, Vladimir M. T1 - Nanodetector: Ultrasensitive plasmonic detection of single nanoparticles T2 - Compendium of Projects in the European Nanosafety Cluster Y1 - 2013 UR - https://www.nanosafetycluster.eu/uploads/files/pdf/2013_NSC_Compendium.pdf VL - 2013 SP - 85 EP - 89 ER - TY - GEN A1 - Mirsky, Vladimir M. T1 - Nanodetector: Ultrasensitive plasmonic detection of single nanoparticles T2 - Compendium of Projects in the European Nanosafety Cluster Y1 - 2014 UR - https://nanoinformation.at/fileadmin_nanoinformation/_migrated/content_uploads/2014_NSC_Compendium_01.pdf VL - 2014 SP - 54 EP - 59 ER - TY - GEN A1 - Mirsky, Vladimir M. T1 - Nanodetector: Ultrasensitive plasmonic detection of single nanoparticles T2 - Compendium of Projects in the European Nanosafety Cluster Y1 - 2015 UR - https://www.nanosafetycluster.eu/uploads/files/pdf/2015_NSC_Compendium.pdf VL - 2015 SP - 83 EP - 89 ER - TY - CHAP A1 - Nizamov, Shavkat A1 - Mirsky, Vladimir M. ED - Kumar, Challa S. S. R. T1 - Wide-field Surface Plasmon Resonance Microscopy for in-situ Characterization of Nanoparticle Suspensions T2 - In-situ characterization techniques for nanomaterials Y1 - 2018 SN - 978-3-662-56322-9 SN - 978-3-662-56321-2 U6 - https://doi.org/10.1007/978-3-662-56322-9 SP - 61 EP - 106 PB - Springer Verlag CY - Heidelberg ER - TY - GEN A1 - Laroussi, Arwa A1 - Kot, Małgorzata A1 - Flege, Jan Ingo A1 - Raouafi, Noureddine A1 - Mirsky, Vladimir M. T1 - Self-assembled monolayers from symmetrical di-thiols: Preparation, characterization and application for the assembly of electrochemically active films T2 - Applied Surface Science N2 - 1,3-dimercaptopropan-2-ol, a symmetrical di-thiol, has been synthesized and applied as a new type of anchor molecule to prepare a self-assembled monolayer (SAM) on the gold surface. The formed monolayers were studied by cyclic voltammetry, impedance spectroscopy, X-ray photoelectron spectroscopy, kinetic capacitance, and contact angle measurements. The SAM structure depends on the adsorption conditions. A short incubation time of the electrode at high concentration of this di-thiol leads to the predominating binding through one thiol group of the adsorbate to the gold surface, while a long incubation at low concentration leads to the predominating binding by both thiol groups. A comparative study of the desorption and replacement of SAMs indicates a strong stability increase when the SAM molecules bond gold surface by two bonds mainly. This monolayer was used to immobilize electrochemically active p-benzoquinone moiety. The surface concentration of p-benzoquinone obtained from cyclic voltammetry is 2.5 ± 0.2 × 10−10 mol·cm−2 which corresponds to the functionalization of 65 ± 5% of SAM molecules. The obtained highly stable SAM with redox-active terminal group can be applied for different tasks of chemical sensing and biosensing. As an example, an application of this system for electrocatalytical oxidation of dihydronicotinamide adenosine dinucleotide (NADH) was tested. KW - self-assembled monolayer (SAM) KW - cyclic voltammetry KW - impedance spectroscopy KW - X-ray photoelectron spectroscopy (XPS) KW - kinetic capacitance KW - contact angle Y1 - 2020 U6 - https://doi.org/10.1016/j.apsusc.2020.145827 SN - 0169-4332 SN - 1873-5584 VL - 513 ER - TY - GEN A1 - Mirsky, Vladimir M. T1 - Electrochemical sensors between the academic world and harsh reality: a few thoughts on the past, present, and future T2 - Journal of Solid State Electrochemistry Y1 - 2020 U6 - https://doi.org/10.1007/s10008-020-04711-1 SN - 1433-0768 SN - 1432-8488 VL - 24 IS - 9 SP - 2147 EP - 2149 ER - TY - GEN A1 - Efremenko, Yulia A1 - Mirsky, Vladimir M. T1 - Poly-3-thienylboronic acid: a chemosensitive derivative of polythiophene T2 - Journal of Solid State Electrochemistry N2 - Poly-3-thiopheneboronic acid was synthesized by electrochemical polymerization from 3-thienylboronic acid dissolved in the mixture of boron trifluoride diethyl etherate and acetonitrile. Cyclic voltammetry during electropolymerization shows oxidative and reductive peaks growing in each next cycle. An investigation by scanning electron microscopy displayed the polymer layer like a highly flexible film of 110 nm thick with grains of 60–120 nm in size. Strong negative solvatochromic effect was observed. Optical spectra of poly-3-thienylboronic acid at different potentials and pH were studied. Potential cycling leads to a well reversible electrochromic effect. At pH 7.4, the increase of potential leads to the decrease in the absorption band at 480 nm and to the rise in the absorption band at 810 nm with an isosbestic point at 585 nm. Spectroelectrochemical behavior of poly-3-thienylboronic acid and polythiophene was compared. Binding of sorbitol at fixed electrode potential leads to an increase in the absorbance in the shortwave band and to the decrease in the longwave band; the effect depends on the electrode potential and pH. Perspectives of application of poly-3-thienylboronic acid as new chemosensitive material are discussed. KW - Chemosensitive conducting polymers KW - Polythiophene KW - Poly-3-thienylboronic acid KW - Spectroelectrochemistry KW - Sorbitol sensing Y1 - 2020 U6 - https://doi.org/10.1007/s10008-020-04767-z SN - 1433-0768 SN - 1432-8488 VL - 24 IS - 11-12 SP - 3105 EP - 3111 ER - TY - GEN A1 - Snopok, Borys A. A1 - Laroussi, Arwa A1 - Cafolla, Clodomiro A1 - Voitchovsky, Kislon A1 - Snopok, Tetiana V. A1 - Mirsky, Vladimir M. T1 - Gold surface cleaning by etching polishing: Optimization of polycrystalline film topography and surface functionality for biosensing T2 - Surfaces and Interfaces N2 - Modern bio-chemical sensors rely on functional interfacial architectures with well-defined structural nano-motifs over a physical transducer. Gold-coated interfaces are of particular interest for their desirable chemical (functionalization) and optical (plasmonic) properties. Here we investigate the cleaning and polishing of polycrystalline gold films in preparation of advanced surface functionalization. We focus on soft wet chemical etching to decrease the small-scale roughness commonly observed after evaporation or sputtering of gold. We show that optimized surfaces are obtained by etching in solutions of hydrochloric acid and hydrogen peroxide. We systematically quantify the films wettability, surface nano-topography, UV-VIS spectrum and the electrochemical and Surface Plasmon Resonance (SPR) changes throughout the etching process. Optimal results are obtained by etching with a HCl(37%):H2O2(30%):H2O mixture, with a volume ratio of reagents 3:3:94 during 15-20 minutes at room temperature for the main step. This reduces by a factor two the root-mean-square roughness, removes contaminants, increases hydrophilicity and modifies the gold surface by Au(Cl)x complexes. Significantly, the resulting the surface is hydrophilic enough to prevent globular proteins such as HSA to unfold upon deposition at concentrations more than ~1 mg/mL. Our protocol offers a simple, reliable and rapid method for the preparation of gold surface in view of further functionalization including the binding of receptor layers and various micro- and nanostructures required in chemical and biochemical sensing. KW - polycrystalline gold films KW - soft wet chemical polishing KW - gold cleaning KW - hydrochloric acid and hydrogen peroxide KW - protein adsorption KW - surface plasmon resonance Y1 - 2021 U6 - https://doi.org/10.1016/j.surfin.2020.100818 SN - 2468-0230 VL - 22 ER - TY - GEN A1 - Laurinavichyute, Veronika K. A1 - Nizamov, Shavkat A1 - Mirsky, Vladimir M. T1 - Real time tracking of the early stage of electrochemical nucleation T2 - Electrochimica Acta N2 - An analysis of early stage of electrochemical nucleation is crucial in order to understand the mechanism of this process and for electrochemical synthesis of new materials. We show here an application of the wide field surface plasmon microscopy (WF-SPRM) for this purpose. It allows us in-situ monitoring of the growth of nuclei in the range from ~20 till over 1000 nm. The system registers the moment and the place of the formation of each individual nucleus for the total number of the tracked nuclei up to ~10,000 per 1 mm2. The results demonstrate that the integral information obtained from electrochemical measurements can be extracted quantitatively from optical measurements while optical data provide also information on the size of each individual nucleus, individual nucleation time, localization and growth kinetics, and allows one to distinguish the rate limiting stage for each individual nucleus. In this work WF-SPRM was applied for investigation of electrochemical deposition of copper on gold, but this technique can be extended easily to other materials or other nucleation types. KW - Surface plasmon resonance microscopy KW - Nucleation and growth KW - Copper deposition KW - Growth kinetics KW - Diffusion zones Y1 - 2021 U6 - https://doi.org/10.1016/j.electacta.2021.138278 SN - 0013-4686 VL - 382 ER - TY - GEN A1 - Laroussi, Arwa A1 - Raouafi, Noureddine A1 - Mirsky, Vladimir M. T1 - Electrocatalytic Sensor for Hydrogen Peroxide Based on Immobilized Benzoquinone T2 - Electroanalysis N2 - An amperometric chemosensor for the detection of hydrogen peroxide is reported. The sensor is based on 1,4-benzoquinone immobilized on the gold electrode using self-assembled monolayer of short chain symmetrical dithiol as an anchor layer. Sensor analysis was performed by cyclic voltammetry at the potential range from −0.6 V till +0.9 V as well as in the anodic or cathodic potential ranges only. The results indicate oxidative electrochemical decomposition of hydrogen peroxide at the potential of ∼+0.4 V leading to the formation of oxygen while at cathodic potentials a reduction of the formed oxygen as well as of the hydrogen peroxide occur. A decrease in the oxidation potential of hydrogen peroxide on the gold electrode coated by self-assembled monolayer with 1,4-benzoquinone in comparison with that measured on the electrodes coated by the same self-assembled monolayer without 1,4-benzoquinone, indicates electrocatalytic effect of this moiety on oxidative decomposition of hydrogen peroxide. Analytical evaluation of the sensor performance was done in the voltammetric as well as in the chronoamperometric mode. The sensor exhibited linear response over the concentration range till 2.5 mM with a limit of detection ∼4 μM. KW - Hydrogen peroxide KW - Chemical sensor KW - Electrocatalysis KW - Benzoquinone KW - Self-assembled monolaye Y1 - 2021 U6 - https://doi.org/10.1002/elan.202100113 SN - 1521-4109 VL - 33 IS - 9 SP - 2062 EP - 2070 ER - TY - GEN A1 - Laroussi, Arwa A1 - Kot, Małgorzata A1 - Flege, Jan Ingo A1 - Raouafi, Noureddine A1 - Mirsky, Vladimir M. T1 - Self-Assembled Monolayers from Symmetrical Di-Thiols: Preparation, Characterization and Application for the Assembly of Electrochemically Active Films T2 - Engineering Proceedings N2 - 1,3-dimercaptopropan-2-ol, a symmetrical di-thiol, has been synthesized and applied as a new type of anchor molecule to prepare a self-assembled monolayer (SAM) on a gold surface. The formed monolayers were studied by cyclic voltammetry, impedance spectroscopy, X-ray photoelectron spectroscopy, kinetic capacitance, and contact angle measurements. The SAM structure depends on the adsorption conditions. A short incubation time of the electrode at high concentration of this di-thiol leads to the predominating binding through one thiol group of the adsorbate to the gold surface, while a long incubation at low concentration leads to the predominating binding by both thiol groups. A comparative study of the desorption and replacement of SAMs indicates a strong stability increase when the SAM molecules bond gold surfaces by two bonds mainly. This monolayer was used to immobilize electrochemically active p-benzoquinone moiety. The surface concentration of p-benzoquinone obtained from cyclic voltammetry is 2.5 ± 0.2 × 10−10 mol cm−2, which corresponds to the functionalization of 65 ± 5% of SAM molecules. The obtained highly stable SAM with redox-active terminal group can be applied for different tasks of chemical sensing and biosensing. As an example, an application of this system for electrocatalytical oxidation of dihydronicotinamide adenosine dinucleotide (NADH) was tested. KW - self-assembled monolayer KW - immobilization fashion KW - X-ray photoelectron spectroscopy KW - p-benzoquinone KW - electron transfer KW - cyclic voltammetry KW - NADH sensor Y1 - 2021 U6 - https://doi.org/10.3390/I3S2021Dresden-10112 SN - 2673-4591 N1 - Presented at the 8th International Symposium on Sensor Science, 17–28 May 2021 VL - 6 IS - 1 ER - TY - GEN A1 - Nizamov, Shavkat A1 - Dimchevska Sazdovska, Simona A1 - Mirsky, Vladimir M. T1 - A review of optical methods for ultrasensitive detection and characterization of nanoparticles in liquid media with a focus on the wide field surface plasmon microscopy T2 - Analytica Chimica Acta N2 - Development of nanotechnology and corresponding industries during the last decade resulted in a new challenge for analytical science. This includes an ultrasensitive detection and characterization of nanoparticles of different origin and other nanomaterials in various media, including so complex ones as food, biological or environmental samples. The goal of this review is a systematic analysis of possible approaches and description of physical principles behind these methods. The main attention is paid to optical methods which are considered by authors to be mostly effective for the formulated task. Different approaches for detection and analysis of nanoparticles in a volume as well as of those adsorbed on a surface are discussed. While the technologies based on direct analysis of nanoparticle suspensions belong to the established approaches whose development potential has been in large extent exhausted, the novel technologies based on the surface sensing of adsorbed nanoparticles demonstrate intensive development. Therefore, the final part of the review is focused on the wide-field surface plasmon resonance microscopy. It allows one an ultrasensitive detection and characterization of individual nanoparticles of different origin in complex media and provides numerous possibilities for subsequent chemical identification of the detected particles using a hyphenation with other analytical technologies. KW - Nanoparticles KW - Detection of nanoparticles KW - Characterization of nanoparticles KW - Optical techniques KW - Surface plasmon resonance microscopy KW - Nanoparticle tracking analysis Y1 - 2022 U6 - https://doi.org/10.1016/j.aca.2022.339633 SN - 1873-4324 VL - 1204 ER - TY - GEN A1 - Karačić, Dalibor A1 - Gutić, Sanjin J. A1 - Vasić, Borislav A1 - Mirsky, Vladimir M. A1 - Skorodumova, Natalia V. A1 - Mentus, Slavko V. A1 - Pašti, Igor A. T1 - Electrochemical reduction of thin graphene-oxide films in aqueous solutions – Restoration of conductivity T2 - Electrochimica Acta N2 - Graphene oxide finds applications in different fields of science, including energy conversion. Electrochemical reduction of graphene oxide (GO) significantly improves its conductivity. However, the kinetics of this process depends on the solvent, supporting electrolyte, pH, and numerous other factors. Most studies report the macroscopic views and ex-situ properties of reduced GO. To expand the knowledge about GO reduction, in this study, we used cyclic voltammetry (CV), simultaneous 2 points and 4 points resistance measurement (s24), conductive atomic force microscopy (AFM), and theoretical calculations. Using CV, we demonstrated that the choice of supporting electrolyte (KCl or LiCl) influences the potential range in which electrochemical GO reduction occurs. The activation energy of this process was estimated to be below 30 kJ mol‒1 in both electrolytes, being significantly lower than that required for thermal reduction of GO. Simultaneous in situ s24 resistance measurements suggest that GO films reach a highly conductive state at deep negative potentials, with an abrupt, irreversible switch from non-conductive to the conductive state. However, conductive AFM presents a more exact picture of this process: the reduction of GO films starts locally while the formed conductive islands grow during the reduction. This mechanism was confirmed by theoretical calculations indicating that the reduction starts on isolated oxygen-functional groups over the GO basal plane, while clustered OH groups are more difficult to reduce. The presented results can help in tailoring reduced GO for a particular electrochemical application by precisely controlling the reduction degree and percentage of the conductive area of the reduced GO films. KW - Electrochemical reduction of graphene oxide KW - Supporting electrolyte effect KW - Simultaneous 2-point 4-point resistance measurements KW - Conductive atomic force microscopy KW - Theoretical calculations Y1 - 2022 UR - https://www.sciencedirect.com/science/article/pii/S0013468622002183 U6 - https://doi.org/10.1016/j.electacta.2022.140046 SN - 1873-3859 SN - 0013-4686 VL - 410 ER - TY - GEN A1 - Efremenko, Yulia A1 - Mirsky, Vladimir M. T1 - 3-Thienylboronic Acid as a Receptor for Diol-Containing Compounds: A Study by Isothermal Titration Calorimetry T2 - Chemosensors N2 - The electrochemical activity of 3-thienylboronic acid and its feature to form polymer films makes it a perspective receptor material for sensor applications. The affinity properties of this compound were studied here by isothermal titration calorimetry. A number of different analytes were tested, and the highest binding enthalpy was observed for sorbitol and fructose. An increase of pH in the range of 5.5–10.6 results in the rise of the binding enthalpy with an increase of the binding constant to ~8400 L/mol for sorbitol or ~3400 L/mol for fructose. The dependence of the binding constant on pH has an inflection point at pH 7.6 with a slope that is a ten-fold binding constant per one pH unit. The binding properties of 3-thienylboronic acid were evaluated to be very close to that of the phenylboronic acid, but the electrochemical activity of 3-thienylboronic acid provides a possibility of external electrical control: dependence of the affinity of 3-thienylboronic acid on its redox state defined by the presence of ferro/ferricyanide in different ratios was demonstrated. The results show that 3-thienylboronic acid can be applied in smart chemical sensors with electrochemically controllable receptor affinity. KW - chemical sensors KW - affinity KW - isothermal titration calorimetry KW - 3-thienylboronic acid KW - diol-containing compounds Y1 - 2022 UR - https://www.mdpi.com/2227-9040/10/7/251 U6 - https://doi.org/10.3390/chemosensors10070251 SN - 2227-9040 VL - 10 IS - 7 ER - TY - GEN A1 - Efremenko, Yulia A1 - Mirsky, Vladimir M. T1 - Electrical Control of the Receptor Affinity T2 - Engineering Proceedings N2 - A concept of virtual sensor array based on an electrically controlled variation of affinity properties of the receptor layer was realized on the base of integrated electrochemical chemotransistor containing conducting polymer as the receptor layer. Electrical control of the redox-state of the polymer (polyaniline) was performed in a five-electrode configuration with four electrodes for conductivity measurements and Ag/AgCl reference electrode integrated on the same glass chip. An ionic liquid provided an electrical connection between the reference electrode and chemosensitive material. Conductivity measurements demonstrated potential controlled electrochemical conversions of the receptor material between different redox states. The binding of trimethylamine at three different potentials corresponding to these states was studied. The results demonstrated that both kinetic- and equilibrium-binding properties of the receptor are controlled by the electrical potential, thus providing a possibility to form a virtual sensor array using only a single sensing element. The concept was applied for monitoring fish headspace. Using three characteristics of the sensor response measured at three different redox states of the same sensor material, we obtained signals from a virtual sensor array consisting of nine chemosensitive elements. The sensor displays systematic changes of its nine signals during fish degradation. This approach can be applied also for the electrical control of the affinity of immunoglobulins. Development of new materials with electrically controlled affinity is in progress. KW - conducting polymer KW - affinity KW - virtual sensor array Y1 - 2021 UR - https://www.mdpi.com/2673-4591/6/1/3 U6 - https://doi.org/10.3390/I3S2021Dresden-10084 SN - 2673-4591 N1 - Presented at the 8th International Symposium on Sensor Science, 17–28 May 2021 VL - 6 IS - 1 ER - TY - GEN A1 - Nizamov, Shavkat A1 - Scherbahn, Vitali A1 - Mirsky, Vladimir M. T1 - Detection of Single Sub-Micrometer Objects of Biological or Technical Origin Using Wide Field Surface Plasmon Microscopy T2 - MDPI Proceedings (Journal), Proceedings of the 5th International Symposium on Sensor Science (I3S 2017)) N2 - Detection of nano- and microparticles is an important task for chemical analytics, medical diagnostics, food industry, biotechnology, environmental monitoring and many other fields of science and industry. For this purpose, a method based on the detection and analysis of minute signals of surface plasmon resonance images due to adsorption of single particles was developed. The new technology allows one a real-time detection of interaction of single nano- and microparticles of different origin with sensor surface. Adsorption of each nanoparticle leads to a characteristic diffraction image whose intensity depends on the size and chemical composition of the particle. The number of the nanoparticle - surface binding events per time and surface area characterizes volume concentration. A large monitored surface area of the sensor surface allows one to detect many hundreds events in each frame or totally up to a million particles on the sensor surface, this leads to a very high dynamic range of counting and to a correspondingly high dynamic range in the concentration scale. Depending on the type of particles and experimental conditions, the detection limit for aqueous samples can be below 1000 nanoparticles per microliter. Stable analysis of nanoparticles in very complex environment (fruit juices, wines, cosmetic formulations) was demonstrated. For determination of chemical composition of single nanoparticles separately, the wide field surface plasmon microscopy can be used as a tandem technique. For example, for analysis of technical nanoparticles it can be assisted by electrochemical analysis. In this case, the gold sensor surface is used both for plasmon microscopy and as a working electrode of electrochemical cell. Applying a linear potential sweep to this electrode, adsorbed nanoparticles can be subjected to an electrochemical conversion leading to the change of their refractive index; the value of electrical potential of this conversion characterizes material of the particular nanoparticle. Notably, such analysis is performed simultaneously but independently for each adsorbed particle. The method of wide filed surface plasmon microscopy can be applied for ultrasensitive detection and analysis of nano- and microparticles of biological (bacteria, viruses, exosomes), biotechnological, (liposomes, protein nanoparticles for drug delivery) or technical (metallic, oxides, plastic, etc.) origin. Y1 - 2017 UR - https://www.mdpi.com/2504-3900/1/8/788 U6 - https://doi.org/10.3390/proceedings1080788 VL - 1 IS - 8 PB - MDPI CY - Basel, Switzerland ER - TY - GEN A1 - Efremenko, Yulia A1 - Laroussi, Arwa A1 - Sengül, Akant A1 - Corley-Wiciak, Agnieszka Anna A1 - Fischer, Inga Anita A1 - Mirsky, Vladimir M. T1 - Deposition of Polymers on Titanium Nitride Electrodes T2 - Coatings N2 - The application of titanium nitride (TiN) as an electrode for electrochemical deposition or characterization requires the removal of an insulating layer from its surface. This process was studied and optimized, and the conditions for the complete removal of this layer through treatment with oxalic acid were formulated. The obtained TiN surfaces were used for the deposition of various conducting and non-conducting polymers. Two different approaches were applied: (i) in situ electrochemical synthesis of the main classes of conducting polymers, including polyaniline, polypyrrole, polythiophene, and selected derivatives thereof, and (ii) electrostatically driven layer-by-layer (LbL) deposition of multilayers of oppositely charged polyelectrolytes. The deposited polymers were characterized by electrochemical methods. The electrochemical properties of the deposited conducting polymers and their deposition on the TiN surface were comparable to those of the metallic electrodes. The films produced via LbL deposition exhibited a pronounced influence of the charge of the last deposited polymer on the redox reaction of ferri/ferrocyanide, validating the charge alteration with each successive polymer layer deposition. The studied deposition technologies can be used for the modification of TiN surfaces required in applications of this material in chemical sensors and other devices. Y1 - 2024 U6 - https://doi.org/10.3390/coatings14020215 SN - 2079-6412 VL - 14 IS - 2 ER - TY - GEN A1 - Beisembek, Alisher A1 - Dimchevska Sazdovska, Simona A1 - Mirsky, Vladimir M. T1 - Separation of shifts in surface plasmon resonance into refractive index and thickness of deposited layers T2 - Sensors and actuators. B, Chemical N2 - Routine Surface Plasmon Resonance (SPR) measurements, which are widely applied in affinity (bio)sensors and surface science, do not allow one to separate the obtained SPR signals into the change of the refractive index and thickness of deposited layers. For thin layers the signal is proportional to the product of the layer thickness and the difference in the refractive indices of this layer and of the aqueous media. In this study, we suggest an approach to separate these parameters. It is performed by subsequent measurements in the presence and in the absence of polyethylene glycol (PEG), an inert additive which modifies the refractive index of the liquid phase but do not penetrate into the adsorbed layer. Both parameters were successively determined for human serum albumin (HSA) as well as for anti-HSA IgG in three different settings: i) HSA adsorbed directly onto a gold surface, ii) HSA chemically immobilized on a gold surface coated with a self-assembled monolayer of 1,16 mercaptohexadecanoic acid and iii) chemically immobilized HSA with additional monomolecular layer of anti- HSA IgG antibodies bond to this protein layer. The suggested approach can be applied in most SPR devices with a flow cell for analysis of various adsorbed layers. KW - Surface plasmon resonance KW - Thin layer thickness KW - Refractive index measurement Y1 - 2023 U6 - https://doi.org/10.1016/j.snb.2023.134606 SN - 1873-3077 SN - 0925-4005 VL - 396 ER - TY - GEN A1 - Laroussi, Arwa A1 - Raouafi, Noureddine A1 - Mirsky, Vladimir M. T1 - Electrocatalytical Chemical Sensor for Hydrogen Peroxide T2 - Engineering Proceedings N2 - The fast and selective determination of hydrogen peroxide (H2O2) is of importance not only because of strong interest in this widely applied analyte, but also because of the development of enzymatic biosensors for glucose or other metabolites where the sensor for H2O2 can be used as the transducer. Here, we report on an electrocatalytical amperometric sensor for the detection of H2O2. It is a sensor that consists of a gold electrode covered by a self-assembled monolayer (SAM) with immobilized p-benzoquinone. To provide highly stable immobilization of p-benzoquinone at the distance of effective electron tunneling, a new anchor compound—1,3-dimercaptopropan-2-ol—was synthesized and used for preparation of the SAM. Due to two thiol groups binding gold surface, this compound provides high stability of the SAM. The surface concentration of p-benzoquinone obtained from cyclic voltammetry is 2.5 ± 0.2 × 10−10 mol·cm−2. Cyclic voltammetry and chronoamperometry experiments proved that the immobilized benzoquinone exhibited high electrocatalytic activity towards the decomposition of H2O2. Depending on the used potential range, different sensing modes can be realized. For example, one can measure electrochemical response due to the oxidation of H2O2 at anodic potentials, or due to the reduction of oxygen formed during oxidative decomposition of H2O2. Also, amperometric response at fixed potential of +0.4 V vs. Ag/AgCl corresponding to the oxidation of benzoquinone to hydroquinone was studied. The sensor exhibited a linear response over a concentration range of 0.1–2 mM with a low detection limit of 4.24 µM. The reproducibility of three different electrodes prepared was examined at the H2O2 concentration range from 0.1 till 3 mM, which resulted in a relative standard deviation below 4.2%. KW - self-assembled monolayer KW - p-benzoquinone KW - electron transfer KW - cyclic voltanmetry KW - chronoamperometry KW - hydrogen peroxide KW - electrocatalysis KW - chemical sensor Y1 - 2021 U6 - https://doi.org/10.3390/I3S2021Dresden-10168 SN - 2673-4591 N1 - Presented at the 8th International Symposium on Sensor Science, 17–28 May 2021 VL - 6 IS - 1 ER - TY - GEN A1 - Kolosova, Olga S. A1 - Efremenko, Yulia A1 - Laurinavichyute, Veronika K. A1 - Nizamov, Shavkat A1 - Petrushenko, Serhii I. A1 - Mirsky, Vladimir M. T1 - Poly-3-thienylboronic Acid Nanoparticles: Synthesis, Characterization, and Interaction with Saccharides Studied at the Level of Individual Nanoparticles T2 - ACS Applied Nano Materials N2 - Polythiophenboronic acid (PThBA) combines an affinity for saccharides with the unique properties of conducting polymers. This polymer was synthesized by enzymatic catalyzed oxidative polymerization, characterized by UV–vis spectroscopy in solvents of different polarity and by 1H NMR. A suspension of PThBA nanoparticles (PThBA NPs) was prepared by injecting a methanol solution of PThBA into an aqueous electrolyte. PThBA NPs were characterized by scanning electron microscopy. Nanoparticle tracking analysis and dynamic light scattering were used to study the concentration of the particles and the particle size distribution. The effect of pH on these properties was analyzed and an increase in nanoparticle size was observed at alkaline pH. This effect was explained by electrostatic swelling of the nanoparticles. Measurements of ζ-potentials in the wide pH range showed the presence of acidic groups with a pKa of 8.6; the value of the surface charge at the conditions of maximal deprotonation of these groups was estimated to be ∼70 mC/m2. Changes in the optical spectra of PThBA NPs due to variations in pH and additions of organic solvents indicate transformations between twisted and planar conformations of the polymer backbone. The binding of saccharides by PThBA NPs resulted in a decrease in the size and charge of the nanoparticles. Recently developed wide-field surface plasmon resonance microscopy (WF-SPRM) can simultaneously monitor every single nanoparticle among many thousands adsorbed on a surface. It was used for the first time to study chemosensitive nanoparticles. The described above effects of pH change and saccharide binding described above, monitor were confirmed by using integral techniques in monitoring individual nanoparticles, by WF-SPRM. The pH effects were shown to be reversible. An increase in the affinity of PThBA NPs for saccharides at a more alkaline pH was also observed. A fast recovery of polymer binding sites by a pH decrease was demonstrated. The synthesized and characterized PThBA NPs can be further used for various purposes including analytical assays, chemical sensors, or chemosensitive nanotechnological devices. KW - - KW - conducting polymers KW - chemosensitive nanoparticles KW - saccharides binding KW - affinity control KW - polythienylboronic acid KW - surface plasmon resonance microscopy Y1 - 2024 U6 - https://doi.org/10.1021/acsanm.4c00216 SN - 2574-0970 VL - 7 IS - 10 SP - 11120 EP - 11135 PB - American Chemical Society ER - TY - GEN A1 - Efremenko, Yulia A1 - Mirsky, Vladimir M. T1 - Chemosensitive properties of electrochemically synthesized poly-3-thienylboronic acid: conductometric detection of glucose and other diol-containing compounds under electrical affinity control T2 - Polymers N2 - Due to the presence of the boronic acid moieties, poly-3-thienylboronic acid has an affinity for saccharides and other diol-containing compounds. Thin films of this novel chemosensitive polymer were synthesized electrochemically on the gold surface. The adhesion of the polymer was enhanced by the deposition of a monomolecular layer of thiophenol. The technology was used to fabricate conductometric sensors for glucose and other diol-containing compounds. Simultaneous two- and four-electrode conductivity measurements were performed. The chemical sensitivity to sorbitol, fructose, glucose, and ethylene glycol was studied at different pH and electrode potentials, and the corresponding binding constants were obtained. Depending on the electrode potential, the reciprocal values of the binding constants of glucose to poly-3-thienylboronic acid at neutral pH are in the range of 0.2 mM–1.0 mM. The affinity for glucose has been studied in buffer solutions and in solutions containing the major components of human blood. It was shown that the presence of human serum albumin increases the affinity of poly-3-thienylboronic acid for diol-containing compounds. KW - glucose sensor KW - saccharide sensor KW - chemosensitive polymer KW - poly-3-thienylboronic acid KW - conductometric sensor KW - glucose biosensor Y1 - 2024 U6 - https://doi.org/10.3390/polym16131938 SN - 2073-4360 VL - 16 IS - 13 PB - MDPI AG ER - TY - GEN A1 - Snopok, Borys A. A1 - Nizamov, Shavkat A1 - Snopok, Tetiana V. A1 - Mirsky, Vladimir M. T1 - Agglomeration compaction promotes corrosion of gold nanoparticles T2 - Nanoscale Advances N2 - Engineered nanoparticles are increasingly being used in various areas of human activity. However, the degradation mechanism of nanobodies in harsh environments is still a puzzle for theory and experiment. We report here the results of optical spectroscopy and nanoparticle tracking analysis, quantifying agglomeration and sizing of 50 nm citrate stabilized gold nanoparticles (GNPs) in HCl solutions containing H2O2. The mechanism of a consecutive corrosion reaction of GNPs is discussed within the framework of the near-field approach. We found that the disappearance of single nanoparticles from a suspension does not occur due to their dissolution per se, but is a consequence of the formation of aggregates. The neutralization of electrostatic shielding at high ionic strength allows gold nanoparticles to approach the subnanometer distance within the region of capping defects, at which the Casimir and van der Waals attractive forces dominate. It is suggested that electric field fluctuations in the confined space between highly conductive gold nanoparticles cause complexant-stimulated loss of metal from the core in the contact area. Going beyond the charge screening limitations by constraining the reaction space and reducing the double electrical layer thickness allows for chemical processes flow along otherwise not accessible reaction pathways. Y1 - 2024 U6 - https://doi.org/10.1039/D4NA00109E SN - 2516-0230 VL - 6 IS - 15 SP - 3865 EP - 3877 PB - Royal Society of Chemistry (RSC) ER - TY - GEN A1 - Laurinavichyute, Veronika K. A1 - Nizamov, Shavkat A1 - Mirsky, Vladimir M. T1 - Cyclic voltarefractometry of single TiO₂ nanoparticles in large ensembles in nonaqueous electrolyte T2 - Analytical chemistry N2 - Single nanoparticle (NP) cyclic voltarefractometry (CVR), realized as wide-field surface plasmon resonance microscopy (SPRM) in combination with potential cycling, has been proposed and applied to the in situ study of TiO₂ NPs. Electrochemical activity of TiO₂ is mainly observed outside the electrochemical stability window of water. Therefore, the response of individual anatase (a-TiO₂) and rutile (r-TiO₂) NPs adsorbed on a gold layer was studied in 0.25 M LiClO4 acetonitrile solutions. The use of acetonitrile allows us to exploit a much wider potential window compared to water, while due to the almost identical refractive index (nD = 1.344 and 1.333 for acetonitrile and water, respectively), the conditions of the SPR are not changed. This greatly expands the variety of electrochemical reactions that can be studied by SPR techniques. Cyclic polarization of a-TiO₂ and r-TiO₂ NPs results in pronounced electrochemical and optical responses around −1.55 V and around −1.8 V vs Fc+/Fc, respectively. This specific optoelectrochemical response allows them to be distinguished from other NPs. Based on this difference in characteristic potentials, a mixture of a-TiO₂ and r-TiO₂ NPs can be analyzed by CVR as well. The proposed correction algorithm compensates for the drift in the SPRM background caused by the accompanying formation of insoluble compounds and separates the optical response of the NPs out of the background. The results obtained in the study of this complex system demonstrate the capabilities of the developed analytical method. The CVR can be applied to the quantitative analysis of many other types of NPs in nonaqueous solutions, providing information on the electrochemical properties of each individual particle on the electrode surface. Y1 - 2025 U6 - https://doi.org/10.1021/acs.analchem.4c04181 SN - 0003-2700 SN - 1520-6882 VL - 97 IS - 2 SP - 1160 EP - 1169 PB - American Chemical Society CY - Washington, D.C. ER - TY - GEN A1 - Snopok, Borys A. A1 - Ducke, Jana A1 - Mirsky, Vladimir M. T1 - Recognition of soft agglomerates in liquids : comparison and complementarity upon studying gold nanoparticles by tracking analysis, electron spectroscopy and microscopy T2 - Powder technology N2 - A key part of nanoscience is studying how tiny particles gather together in liquids. However, detecting soft agglomerates in their main population formed by single nanoparticles is challenging, since the pairing can only be revealed through adequate identification. In this study, we investigate the effects of agglomeration 60 nm citrate-stabilized gold by optical spectroscopy, nanoparticle tracking analysis and scanning electron microscopy. Optical spectroscopy is limited in its ability to detect soft agglomerates, indicating their presence only when the plasmonic band is approximated by profiles of different types. Electron microscopy requires optimisation of sampling protocols and substrate choice, but still reflects only the dominant agglomerates presented in suspension. Nanoparticle Tracking Analysis is the only method that allows us to characterise the agglomerates in their undistorted state, displaying their greatest diversity. However, it does not provide any information on their composition and shape. We have shown that a correct workflow leads to good agreement between all three methods with respect to the ratio of the most stable agglomerates and individual nanoparticles in the suspension. A detailed discussion of the observed correlations is presented, allowing us to identify gaps in the theoretical description important for the development of targeted analytical protocols. KW - Soft agglomerates KW - Gold nanoparticles KW - Scanning electron microscopy KW - Nanoparticle tracking analysis KW - Optical spectroscopy of nanoparticles KW - Nanoparticle dimers Y1 - 2026 U6 - https://doi.org/10.1016/j.powtec.2025.121649 SN - 0032-5910 VL - 468 SP - 1 EP - 11 PB - Elsevier BV CY - Amsterdam ER - TY - GEN A1 - Kaya, Berfinsu A1 - Efremenko, Yulia A1 - Mirsky, Vladimir M. T1 - Conductometric chemosensor for saccharides based on thin films of poly(3-thienylboronic) acid : measurements of transversal resistance T2 - Biosensors N2 - Poly(3-thienylboronic acid) (PThBA) has recently been suggested as a conducting polymer with affinity for saccharides. In this study, thin films of this compound were deposited onto gold electrodes. The system obtained was studied as a possible chemical sensor. The measurements were performed by impedance spectroscopy using potassium ferro/ferricyanide as a redox mediator. The thickness of the polymer and the deposition of the adhesive sublayer were optimized to achieve a compromise between the blocking of defects in the polymer layer and the unnecessary increase in the internal resistance of this conductometric sensor. A comparative study of the influence of fructose, glucose, and sorbitol on transversal polymer resistance was conducted. The binding constants for these saccharides were extracted from the concentration dependencies of sensor conductance. Among them, sorbitol showed the highest affinity with a binding constant up to ~15,000 L·mol−1, followed by fructose (~8700 L·mol−1) and glucose (~4500 L·mol−1). In order to exclude the contribution of the analyte tautomers on the obtained binding constants, measurements of ethylene glycol were also performed. The effects of pH and the redox state of PThBA on its affinity properties were studied, revealing higher affinities at alkaline pH and in oxidized state of the chemosensitive polymer. The developed system has the capacity to be applied in chemical sensors and virtual sensor arrays with electrical affinity control. KW - Chemical sensor KW - Saccharide sensor KW - 3-thienylboronic acid KW - Conductometric sensor KW - Electrochemical impedance spectroscopy Y1 - 2025 U6 - https://doi.org/10.3390/bios15100679 SN - 2079-6374 VL - 15 IS - 10 SP - 1 EP - 15 PB - MDPI AG CY - Basel ER - TY - GEN A1 - Sengül, Akant A1 - Reiter, Sebastian A1 - Lotfi, Zahra A1 - Efremenko, Julia A1 - Laroussi, Arwa A1 - Corley-Wiciak, Agnieszka Anna A1 - Ratzke, Markus A1 - Mirsky, Vladimir M. A1 - Wenger, Christian A1 - Fischer, Inga Anita T1 - Titanium nitride plasmonic nanohole arrays with polymer coating : optical properties and their humidity-induced modifications T2 - Optical materials express N2 - The use of titanium nitride (TiN) for the fabrication of plasmonic structures such as nanohole arrays (NHAs) can enable their integration into optoelectronic devices on the silicon (Si) platform, for example, for the realization of on-chip chemical sensors and biosensors based on refractometric transduction. With a corresponding functionalization of the TiN nanohole arrays, these ultra-compact devices can be utilized in the development of various affinity sensors and sensor systems, such as cost-effective electronic noses for the early detection of gases in the food industry or agriculture. In this work, we focus on two types of coating for functionalization of TiN nanohole arrays: electrochemically synthesized poly-N-methylaniline and layer-by-layer deposited polyacrylic-acid/poly-allylamine (PAA/PAH). Our investigation comprises the experimental characterization of the optical properties of TiN nanhole arrays coated with polymer layers of different thicknesses as well as a comparison with simulation results. We demonstrate the potential of our setup sensing applications by measuring changes in optical properties of TiN nanohole arrays coated with PAA/PAH upon exposure to air of different humidity. Y1 - 2026 U6 - https://doi.org/10.1364/ome.578871 SN - 2159-3930 VL - 16 IS - 2 SP - 184 EP - 196 PB - Optica Publishing Group CY - Washington, DC ER -