TY - GEN A1 - Efremenko, Yulia A1 - Mirsky, Vladimir M. T1 - Electrically controlled variation of receptor affinity T2 - Analytical and Bioanalytical Chemistry N2 - A concept of virtual sensor array based on electrically controlled variation of affinity properties of the receptor layer is described. It was realized on the base of integrated electrochemical chemotransistor containing polyaniline as the receptor layer. Electrical control of the redox state of polyaniline was performed in five-electrode configuration containing four electrodes for conductivity measurements and one Ag/AgCl reference electrode. All the electrodes were integrated on the same glass chip. A room-temperature ionic liquid was used for the electrical connection between the reference electrode and chemosensitive material. Conductivity measurements demonstrated effective potential-controlled electrochemical conversions of the receptor material between different redox states. Binding of trimethylamine at three different potentials, corresponding to the different states of the receptor material, was studied. Concentration dependencies and binding kinetics were analyzed. The results demonstrated that the kinetic as well as the equilibrium binding properties of the receptor layer can be controlled by electrical potential, thus providing a possibility to form a virtual sensor array using only a single sensing element. Y1 - 2016 U6 - https://doi.org/10.1007/s00216-016-9751-1 SN - 1618-2650 VL - 408 IS - 26 SP - 7287 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 - 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 - 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 - 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 - 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 - 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 -