TY - GEN A1 - Wolpert, Benjamin A1 - Leitl, Michael A1 - Pfitzner, Arno A1 - Mirsky, Vladimir M. T1 - Chemosensitive properties of electrically conductive Cu(I)-compounds at room temperature T2 - Sensors and Actuators B: Chemical N2 - Changes of the electrical conductance of a number of inorganic copper(I) conductive compounds including Cu₁₂Sb₄S₁₃,CU₂O, CuI, CuBr and CuCl were tested on exposure to different gases and vapors, including ammonia, nitrogen monoxide, octanethiol, hydrogen chloride, acetic acid, formic acid, ethanol, humidity and piperidine. The sensitivity of the resistivity to ammonia was estimated as 2.7%/ppm for CuBr,1.4%/ppm for Cu₂O, 1.2%/ppm for CuCl, 0.013%/ppm for CuI, but only 0.0028%/ppm for Cu₁₂Sb₄S₁₃. The highest selectivity for ammonia was observed for Cu₁₂Sb₄S₁₃. The sensitivity patterns of these materials to the tested gases and vapors are very different which makes them applicable for sensor arrays for identification and quantification of these species. KW - Chemical sensor KW - Gas sensor KW - Ammonia sensor KW - Conductometric sensor KW - Chemoresistor KW - Copper(I) Y1 - 2008 U6 - https://doi.org/10.1016/j.snb.2008.06.047 SN - 0925-4005 VL - 134 IS - 2 SP - 839 EP - 842 ER - TY - GEN A1 - Ivanov, Svetlozar D. A1 - Tsakova, Vessela T. A1 - Mirsky, Vladimir M. T1 - Conductometric transducing in electrocatalytical sensors: Detection of ascorbic acid T2 - Electrochemistry Communications N2 - Conductometric transducing is suggested for electrocatalytic chemical sensors based on conductive polymers. Lateral conductivity of the polymer layers was measured by two- and four-point techniques. The approach was applied for electroanalytical detection of ascorbic acid on the electrocatalytically active polyaniline and poly-ortho-methoxyaniline electrodes. Both polymers displayed a monotonous concentration dependence of their conductance in the analytically important sub-millimolar concentration range of ascorbic acid. The approach was tested in model solutions of ascorbic acid in buffer and applied for detection of ascorbic acid in orange juice. KW - Chemical sensor KW - Conductometric sensor KW - Ascorbic acid KW - Electrocatalytical sensor KW - Electroactive polymers KW - Polyaniline KW - Poly-ortho-methoxyaniline Y1 - 2006 U6 - https://doi.org/10.1016/j.elecom.2006.02.006 SN - 1388-2481 VL - 8 IS - 4 SP - 643 EP - 646 ER - TY - GEN A1 - Panasyuk-Delaney, Tanya A1 - Mirsky, Vladimir M. A1 - Ulbricht, Mathias A1 - Wolfbeis, Otto S. T1 - Impedometric herbicide chemosensors based on molecularly imprinted polymers T2 - Analytica Chimica Acta N2 - The technique of grafting polymerization has been used for preparation of thin films of molecularly imprinting polymers on the surface of polypropylene membranes and on hydrophobized gold electrodes. The herbicide desmetryn was used as a template. The solid supports used were hydrophobic, while the polymer was hydrophilic. The adsorbed layer of benzophenone, irradiated by UV-light, initiated a radical polymerization near the surface. Polymer films were characterized by weighing, contact angle measurements and impedance spectroscopy. The electrodes coated with the molecularly imprinted polymers displayed fairly specific binding of desmetryn, as detected by the decrease in the capacitance of the electrode. Only small capacitive effects were observed on addition of terbumeton or atrazine, while metribuzine displayed capacitance decrease similar to desmetryn. KW - Molecular imprinting KW - Capacitive sensor KW - Chemical sensor KW - Grafting polymerization KW - Photopolymerization Y1 - 2001 U6 - https://doi.org/10.1016/S0003-2670(00)01280-0 SN - 0003-2670 VL - 435 IS - 1 SP - 157 EP - 162 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 - 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 - 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 -