TY - GEN A1 - Drexler, Christoph A1 - Shishkanova, Tatiana V. A1 - Lange, Christoph A1 - Danilov, Sergey N. A1 - Weiss, Dieter A1 - Ganichev, Sergey D. A1 - Mirsky, Vladimir M. T1 - Terahertz split-ring metamaterials as transducers for chemical sensors based on conducting polymers: a feasibility study with sensing of acidic and basic gases using polyaniline chemosensitive layer T2 - Microchimica Acta N2 - We report on the first application of terahertz metamaterials acting as transducers for chemical sensors based on conducting polymers. In our feasibility study aimed at sensing of gaseous hydrochloric and ammonia, a two-dimensional sensor metamaterial consisting of an array of split-ring resonators on the surface of undoped silicon wafer was prepared. The surface of the resonator was coated with a 150-μm layer of polyaniline. Binding of hydrogen chloride to polyaniline leads to distinct changes in the resonance frequency of the metamaterial. Measurements can be performed both in the reflection and transmission mode. A numerical simulation of the response revealed an increase of both the real and the imaginary components of the dielectric function of the polyaniline film. These changes are attributed to the transition from emaraldine base to emeraldine salt. The results demonstrate a new approach for formation of highly sensitive transducers for chemical sensors. Y1 - 2014 U6 - https://doi.org/10.5283/epub.31493 SN - 1436-5073 VL - 181 SP - 1857 EP - 1862 ER - TY - GEN A1 - Barig, Susann A1 - Schiemann, Manja A1 - Mirsky, Vladimir M. A1 - Stahmann, Klaus-Peter T1 - Quantitative turbidity assay for lipolytic enzymes in microtiter plates T2 - Analytical and Bioanalytical Chemistry N2 - A clearing assay for lipolytic enzymes has been realized in 96-well microtiter plates. A thin layer containing emulsified tributyrin as turbidity-generating substrate was placed on a thicker supporting aqueous layer. Both layers were stabilized by a gel-forming agent. Enzyme addition leads to clearing of the emulsion detected with a standard microtiter plate reader as a decrease of extinction. Dependencies of the signal kinetics on the substrate and enzyme concentrations were studied. For 0.5–1 % tributyrin content the reaction rate is not substrate-limited. An initial slope of the signal kinetics is proportional to the lipase activity. A detailed characterization of the assay was performed. Lipolysis of tributyrin was confirmed by glycerol detection. Various gel-forming agents were compared and diffusion conditions in these gels were analyzed. Agar and agarose were found to be the most suitable gel-forming agents, which do not affect enzyme diffusion whereas polyacrylamide gels block lipase diffusion and therefore are not suitable for the assay. The optimized assay prepared from 1 % tributyrin emulsion in 2 % agar gel was tested with six microbial lipases and porcine pancreatic lipase. The detection limit is 20–60 ng/well which is equivalent to 30 μU/well for T. lanuginosus lipase. KW - Lipase assay KW - Lipolytic enzymes KW - Microtiter plates KW - Turbidity KW - Tributyrin Y1 - 2013 U6 - https://doi.org/10.1007/s00216-013-7283-5 SN - 1618-2650 VL - 405 IS - 26 SP - 8539 EP - 8547 ER - TY - GEN A1 - Lange, Ulrich A1 - Mirsky, Vladimir M. T1 - Electroanalytical measurements without electrolytes: Conducting polymers as probes for redox titration in non-conductive organic media T2 - Analytica Chimica Acta N2 - Electroanalytical methods have been applied only in conducting media. An application of conducting polymers allows to overcome this limitation. If such material is in electrochemical equilibrium with dissolved redox active species, its electrical conductivity depends on the redox potential of these species. Therefore, conductometric measurements with conducting polymers can provide about the same information as classical redox electrodes. The approach was applied for redox titration. Equivalent points obtained by this titration in aqueous and organic electrolytes were identical. Then the approach was applied for determination of bromine number by redox titration in non-conducting organic phase. KW - Conducting polymers KW - Redox titration KW - Conductometric sensors KW - Non-conductive media Y1 - 2012 U6 - https://doi.org/10.1016/j.aca.2012.07.024 SN - 0003-2670 VL - 744 SP - 29 EP - 32 ER - TY - GEN A1 - Lange, Ulrich A1 - Mirsky, Vladimir M. T1 - Polythiophene films on gold electrodes: A comparison of bulk and contact resistances in aqueous and organic media T2 - Journal of Solid State Electrochemistry N2 - Recently, developed technique for separated analysis of bulk and contact resistance was applied for the investigation of polythiophene films electropolymerized in boron trifluoride diethylether. Kinetics of polymer resistance and for the first time of the contact resistance during polymer oxidation and reduction were characterized. Influence of electrochemically controlled oxidation state on the polymer bulk and the polymer/metal contact resistance was measured in aqueous and organic environment. Variation of the electrical potential from −0.2 to 1.1 V vs. Ag/AgCl (sat) leads to an increase of the polymer conductivity for about three orders of magnitude and to a decrease of the contact resistance for about three orders of magnitude. The potential dependence of the two resistances was different, especially at high anodic potentials. In organic solution, the change of both resistances was more than six orders of magnitude. The results were compared with electrochemical and spectroelectrochemical data, a difference in the material behavior depending on the electrolyte solvent was observed. The influence of electrical potential on polymer resistance in aqueous solution was explained quantitatively by a three-state model with the values of oxidation potential +0.3 and +1.2 V. KW - Polythiophene KW - In situ conductivity measurement KW - s24-Technique KW - Spectroelectrochemistry KW - Conducting polymers Y1 - 2011 U6 - https://doi.org/10.1007/s10008-011-1450-4 SN - 1433-0768 VL - 15 IS - 11 SP - 2377 EP - 2382 ER - TY - GEN A1 - Nizamov, Shavkat A1 - Mirsky, Vladimir M. T1 - Self-referencing SPR-biosensors based on penetration difference of evanescent waves T2 - Biosensors and Bioelectronics N2 - SPR based biosensors register binding of analytes to the surface with immobilized receptors by measuring changes of the refractive index near this surface. An important task in the improvement of this measurement technology is a separation of signals, corresponding to the changes in the chemosensitive layer, from undesired contributions of bulk phase, for example, due to fluctuations of temperature, concentrations of solutes, pressure. The wavelength of the incident light influences strongly the penetration depth of the corresponding evanescent wave. This dependence was exploited here for compensation of the contribution of the bulk refractive index. It was performed using differential SPR measurements at two wavelengths with differing penetration depths. Theoretical analysis and numerical optimization of the suggested approach, named a Penetration Difference Self-Referencing SPR (PDSR-SPR), were performed. Experimental test was performed using 658 and 980 nm laser diodes. Over 20 times suppression of variations of bulk refractive index with magnitude up to 1000 μRIU was observed. Finally, PDSR-SPR approach was applied for monitoring of antibodies binding to the immobilized antigens. KW - Surface plasmon resonance KW - SPR-biosenso KW - Evanescent wave KW - Affinity senso KW - Immunosensor Y1 - 2011 U6 - https://doi.org/10.1016/j.bios.2011.07.030 SN - 0956-5663 VL - 28 IS - 1 SP - 263 EP - 269 ER - TY - GEN A1 - Lange, Ulrich A1 - Mirsky, Vladimir M. T1 - Integrated electrochemical transistor as a fast recoverable gas sensor T2 - Analytica Chimica Acta N2 - A new design of conductometric chemical sensors based on conducting polymers as chemosensitive elements was suggested. The sensor includes six electrodes. Four inner electrodes coated by chemosensitive polymer are used for simultaneous two- and four-point resistance measurements thus providing information on the bulk polymer resistance and on the resistance of the polymer/electrode contacts. Two outer electrodes wired to inner electrodes by polymeric electrolyte are used for electrical control of redox state of the chemosensitive polymer. The outer electrodes are connected to potentiostat as reference and counter electrodes. It allows us to control redox state of the inner (working) electrodes. This new measurement configuration, resembling chemosensitive electrochemical transistors, provides an internal test of the sensor integrity and an electrically driven sensor regeneration. It was tested as a sensor for the detection of nitrogen dioxide. Polythiophene or polyaniline was used as receptors. Cyclic voltammograms of these polymers on the sensor surface measured in air atmosphere were very similar to that measured in aqueous electrolyte. A control of conductivity of these chemosensitive polymers by electrical potential applied vs. incorporated reference electrode was demonstrated. This effect was used for the regeneration of the chemosensitive material after exposure to nitrogen dioxide: in comparison to usual chemiresistors displaying an irreversible behavior in such test even in the time scale of hours, a completely reversible sensor regeneration within few minutes was observed. KW - Gas sensor KW - Conducting polyme KW - Electrochemical transistor KW - Six-point resistance Measurement KW - Sensor recovery Y1 - 2011 U6 - https://doi.org/10.1016/j.aca.2010.12.008 SN - 0003-2670 VL - 687 IS - 1 SP - 7 EP - 11 ER - TY - GEN A1 - Lange, Ulrich A1 - Mirsky, Vladimir M. T1 - Chemiresistors based on conducting polymers: A review on measurement techniques T2 - Analytica Chimica Acta N2 - This review covers the development of measurement configurations for chemiresistors based on conducting polymers. The simplest chemiresistors are based on application of a two-electrode technique. Artifacts caused by contact resistance can be overcome by application of a four-electrode technique. Simultaneous application of the two- and four-electrode measurement configurations provides an internal control of sensor integrity. An incorporation of two additional electrodes controlling the redox state of chemosensitive polymers and connecting to the measurement electrodes through liquid or (quasi)solid electrolyte results in a six-electrode technique; an electrically driven regeneration of such sensors allows one to perform fast and completely reversible measurements. KW - Chemiresistor KW - Chemotransistor KW - Conducting polymer KW - Chemosensor KW - Contact resistance KW - s24-Technique Y1 - 2011 U6 - https://doi.org/10.1016/j.aca.2010.11.030 SN - 0003-2670 VL - 687 IS - 2 SP - 105 EP - 113 ER - TY - GEN A1 - Lange, Ulrich A1 - Hirsch, Thomas A1 - Mirsky, Vladimir M. A1 - Wolfbeis, Otto S. T1 - Hydrogen sensor based on graphene - palladium nanocomposite T2 - Electrochimica Acta N2 - A composite material was prepared from graphene and palladium nanoparticles (PdNP) by layer-by-layer deposition on gold electrodes. The material was characterized by absorption spectroscopy, scanning electron microscopy, Raman spectroscopy and surface plasmon resonance. Cyclic voltammetry demonstrated the presence of electrocatalytic centers in the palladium decorated graphene. This material can serve as a sensor material for hydrogen at levels from 0.5 to 1% in synthetic air. Pure graphene is poorly sensitive to hydrogen, but incorporation of PdNPs increases its sensitivity by more than an order of magnitude. The effects of hydrogen, nitrogen dioxide and humidity were studied. Sensor regeneration is accelerated in humid air. The sensitivity of the nanocomposite depends on the number of bilayers of graphene–PdNPs. KW - Graphene KW - Palladium KW - Nanoparticle KW - Sensor KW - Layer-by-layer Y1 - 2011 U6 - https://doi.org/10.1016/j.electacta.2010.10.078 SN - 0013-4686 VL - 56 IS - 10 SP - 3707 EP - 3712 ER - TY - GEN A1 - Lange, Ulrich A1 - Mirsky, Vladimir M. T1 - Chemosensitive nanocomposite for conductometric detection of hydrazine and NADH T2 - Electrochimica Acta N2 - A new chemosensitive material based on palladium nanoparticles and PEDOT-PSS is described. The composite was characterized by transmission electron microscopy, cyclic voltammetry and in situ resistance measurements. The material was applied for conductometric detection of hydrazine and NADH. Upon exposure to these analytes PEDOT is reduced leading to an increase in its conductance. This process is catalyzed by palladium. A model for description of the potential dependence of polymer conductivity was suggested, tested and applied for the development of new calibration procedure of chemiresistors based on electroactive polymers. KW - Chemosensor KW - Chemiresistor KW - Nanoparticles KW - Palladium KW - PEDOT KW - Hydrazine KW - NADH Y1 - 2011 U6 - https://doi.org/10.1016/j.electacta.2010.08.092 SN - 0013-4686 VL - 56 IS - 10 SP - 3679 EP - 3684 ER - TY - GEN A1 - Nizamov, Shavkat A1 - Scherbahn, Vitali A1 - Mirsky, Vladimir M. T1 - Detection and quantification of single engineered nanoparticles in complex samples using template matching in wide-field surface plasmon microscopy T2 - Analytical Chemistry N2 - An ultrasensitive analytical method for direct detection of single nanoparticles in complex environment is described. The method relies on the wide-field surface plasmon microscopy (SPM). The suppression of matrix effects is achieved by image analysis based on the template matching. First, characteristic SPM images of nanoparticles are collected in aqueous suspensions. Then the detection of nanoparticles in complex environment is performed using template matching. Quantification and characterization of nanoparticles size was demonstrated at subppb level (∼ 100 pg/mL) in such complex media as wines, fruit juices, or cosmetic formulation. Visualization of the nanoparticles is performed in real time. The method does not require any sample pretreatment. If the minimally acceptable adsorption rate is defined as one nanoparticle to the whole sensor surface per few seconds, the working range of the method is ∼ 10 6 to 10 10 nanoparticles per mL. Y1 - 2016 U6 - https://doi.org/10.1021/acs.analchem.6b02878 SN - 1520-6882 VL - 88 IS - 20 SP - 10206 EP - 10214 ER - TY - CHAP A1 - Yatsimirsky, Anatoly K. A1 - Mirsky, Vladimir M. ED - Mirsky, Vladimir M. ED - Yatsimirsky, Anatoly K. T1 - Quantitative affinity data on selected artificial receptors T2 - Articicial receptors for chemical sensors KW - affinity data KW - artificial receptors KW - molecularly imprinted polymers KW - receptor–analyte binding constants KW - spreader-bar systems Y1 - 2011 SN - 978-3-527-32357-9 U6 - https://doi.org/10.1002/9783527632480 SP - 441 EP - 462 PB - Wiley VCH Verlag CY - Weinheim ER - TY - CHAP A1 - Mirsky, Vladimir M. ED - Mirsky, Vladimir M. ED - Yatsimirsky, Anatoly K. T1 - Quantitative characterization of affinity properties of immobilized receptors T2 - Artificial Receptors for Chemical Sensors KW - adsorption isotherms KW - affinity properties KW - binding isotherm KW - Frumkin isotherm KW - immobilized receptors KW - Langmuir isotherm KW - quantitative characterization KW - sensors Y1 - 2011 SN - 978-3-527-32357-9 U6 - https://doi.org/10.1002/9783527632480.ch1 SP - 1 EP - 15 PB - Wiley-VCH Verlag CY - Weinheim ER - TY - CHAP A1 - Lange, Ulrich A1 - Roznyatovskaya, Nataliya V. A1 - Hao, Qingli A1 - Mirsky, Vladimir M. ED - Mirsky, Vladimir M. ED - Yatsimirsky, Anatoly K. T1 - Conducting polymers as artificial receptors in chemical sensors T2 - Artificial receptors for chemical sensors KW - artificial receptors polyaniline KW - chemosensors KW - conducting polymers KW - polyaniline KW - transducers Y1 - 2011 SN - 978-3-527-32357-9 U6 - https://doi.org/10.1002/9783527632480.ch12 SP - 363 EP - 392 PB - Wiley-VCH CY - Weinheim ER - TY - GEN A1 - Ivanov, Svetlozar D. A1 - Lange, Ulrich A1 - Tsakova, Vessela T. A1 - Mirsky, Vladimir M. T1 - Electrocatalytically active nanocomposite from palladium nanoparticles and polyaniline: Oxidation of hydrazine T2 - Sensors and Actuators B: Chemical N2 - The layer by layer (LbL) adsorption technique was used to deposit a new electrocatalytic material consisting of palladium nanoparticles (Pd NPs) and polyaniline (PANI). As far as PANI adsorption did not affect the reactivity of the Pd NPs attached in the former adsorption step, the LbL technique offered the way of increasing the reactive Pd surface within a three-dimensional nanocomposite structure. In situ conductance measurements have shown that depending on the concentration of the PANI solution, used for the LbL adsorption, composites with either PANI-like (dependent on potential and pH) or metal-like (non-dependent on potential and pH) conductive behaviour can be obtained. Metal-like Pd NPs–PANI nanocomposites were studied as electrocatalytic materials for hydrazine oxidation. A linear concentration dependence of the voltammetric peak currents was observed in the 40–800 μM hydrazine concentration range, the sensitivity increasing with the amount of adsorbed Pd NPs. Amperometric measurements showed linear response in the 10–300 μM range with sensitivity 0.5 μA/μmol cm−2 and a theoretical detection limit estimated to be 0.06 μM. KW - Conducting polymers KW - Pd-nanoparticles KW - LbL adsorption KW - Hydrazine Y1 - 2010 U6 - https://doi.org/10.1016/j.snb.2010.07.004 SN - 0925-4005 VL - 150 IS - 1 SP - 271 EP - 278 ER - TY - GEN A1 - Fassold, Alexander A1 - Falk, Werner A1 - Anders, Sven A1 - Hirsch, Thomas A1 - Mirsky, Vladimir M. A1 - Straub, Rainer H. T1 - Soluble neuropilin-2, a nerve repellent receptor, is increased in rheumatoid arthritis synovium and aggravates sympathetic fiber repulsion and arthritis T2 - Arthritis and Rheumatology N2 - In inflammatory lesions, sympathetic nerve fibers disappear soon after the start of inflammation. We identified sympathetic nerve repellents as possible causal agents in rheumatoid arthritis (RA). On nerve terminals, repellent factors bind to neuropilin-2 and its coreceptor. The aim of this study was to investigate the role of neuropilin-2 in the synovial tissue of patients with RA and patients with osteoarthritis (OA) and in experimental arthritis. The density of neuropilin-2–positive fibers and cells positive for semaphorin 3F (a sympathetic repellent) was investigated using immunofluorescence staining. Enzyme-linked immunosorbent assay was used to detect soluble neuropilin-2 in body fluids from patients with RA and patients with OA. An axon outgrowth assay and a neuropilin-2 Fc fusion construct (neuropilin-2Fc) were used to investigate semaphorin 3F–induced sympathetic nerve repulsion. In an animal model of type II collagen–induced arthritis, soluble neuropilin-2Fc was studied in vivo. The synovial density of neuropilin-2–positive sympathetic nerve fibers was lower in RA than in OA, but the density of cells positive for semaphorin 3F was similar. In synovial fluid, the level of soluble neuropilin-2 was markedly higher in RA compared with OA. Mouse sympathetic ganglia served as an excellent model with which to study semaphorin 3F–induced nerve fiber repulsion. Neuropilin-2 and its coreceptor were present on sympathetic neurons, and semaphorin 3F bound to neuropilin-2Fc (binding constant 96 nmoles/liter). Semaphorin 3F dose-dependently increased sympathetic nerve fiber repulsion (at a 50% maximum response concentration of 160–210 nmoles/liter). In contrast to our expectations, soluble neuropilin-2Fc did not inhibit repulsion but increased the repellent effect of semaphorin 3F. In experimental arthritis, therapy with neuropilin-2Fc aggravated arthritis. Soluble neuropilin-2 has no antirepellent activity but aggravates sympathetic nerve fiber repulsion and arthritis. Increased shedding of neuropilin-2 is probably an unfavorable sign in RA. Y1 - 2009 U6 - https://doi.org/10.1002/art.24860 SN - 2326-5205 VL - 60 IS - 10 SP - 2892 EP - 2901 ER - TY - GEN A1 - Shishkov, Alexander V. A1 - Bogacheva, Elena Nikolaevna A1 - Dolgov, Alexey A. A1 - Chulikov, Alexey L. A1 - Knyazev, Denis G. A1 - Fedorova, Natalia V. A1 - Ksenofontov, Alexander L. A1 - Kordyukova, Larisa V. A1 - Lukashina, Elena V. A1 - Mirsky, Vladimir M. A1 - Baratova, Lyudmila A. T1 - The in situ structural characterization of the influenza A virus matrix M1 protein within a virion T2 - Protein and Peptide Letters N2 - The first attempt has been made to suggest a model of influenza A virus matrix M1 protein spatial structure and molecule orientation within a virion on the basis of tritium planigraphy data and theoretical prediction results. Limited in situ proteolysis of the intact virions with bromelain and surface plasmon resonance spectroscopy study of the M1 protein interaction with lipid coated surfaces were used for independent confirmation of the proposed model. KW - Influenza A virus KW - matrix M1 protein KW - secondary structure prediction KW - tritium planigraphy KW - surface plasmon resonance spectroscopy KW - three-dimensional modeling Y1 - 2009 U6 - https://doi.org/10.2174/092986609789353682 SN - 0929-8665 SN - 1875-5305 VL - 16 IS - 11 SP - 1407 EP - 1413 ER - TY - CHAP A1 - Lange, Ulrich A1 - Mirsky, Vladimir M. ED - Hashmi, S. A. ED - Chandra, A. T1 - Potential and pH-dependencies of bulk and contact resistances of conducting polymers T2 - Electroactive polymers: Materials and devices, Vol. 3 Y1 - 2009 SP - 37 EP - 46 PB - Macmillan Publisher CY - New Delhi ER - TY - GEN A1 - Wolpert, Benjamin A1 - Wolfbeis, Otto S. A1 - Mirsky, Vladimir M. T1 - Gas sensing properties of electrically conductive Cu(I) compounds at elevated temperatures T2 - Sensors and Actuators B: Chemical N2 - Changes in the electrical conductance at 240 °C of a number of copper(I) compounds including CuI, CuBr, Cu2Te, Cu12Sb4S13, (CuI)2P14, and of NiO were measured following the exposure to the gases ammonia, nitrogen dioxide, nitrous oxide, carbon monoxide, carbon dioxide, and propane. Analytical sensitivity and kinetic parameters were compared quantitatively. The high diversity of sensitivity patterns makes these compounds promising candidates for use in sensor arrays. Principal component analysis of the data obtained with a virtual sensor array enabled highly selective sensing of five of the six analytes studied using only two principle components. Activation energies of the charge transport in the materials were determined. KW - Gas sensor KW - Ammonia sensor KW - Conductometric sensor KW - Sensor array KW - Copper(I) KW - High-temperature sensing Y1 - 2009 U6 - https://doi.org/10.1016/j.snb.2009.04.042 SN - 0925-4005 VL - 142 IS - 2 SP - 446 EP - 450 ER - TY - GEN A1 - Ivanov, Svetlozar D. A1 - Kurniawan, Fredy A1 - Tsakova, Vessela T. A1 - Mirsky, Vladimir M. T1 - Automated layer-by-layer deposition of polyelectrolytes in flow mode T2 - Macromolecular Materials and Engineering N2 - Multilayer structures of conducting polymers were fabricated by a simply automated approach in flow mode. Polyaniline and poly(styrene sulfonate) were used as a model system, allowing a fast electrochemical and spectroscopic determination of the amount of deposited material. The technology was applied for layer-by-layer deposition of up to 100 bilayers. The results demonstrate a well reproducible and almost constant amount of the adsorbed polymer at each deposition cycle. The method can be applied for deposition of other conducting or non-conducting polymers, biological macromolecules and composites of polyelectrolytes and nanoparticles. Y1 - 2009 U6 - https://doi.org/10.1002/mame.200800376 SN - 1439-2054 VL - 294 IS - 6-7 SP - 441 EP - 444 ER - TY - CHAP A1 - Potyrailo, Radislav A. A1 - Mirsky, Vladimir M. ED - Ryan, Margaret A. ED - Shevade, Abhijit V. ED - Taylor, Charles J. ED - Homer, M. L. ED - Blanco, Mario ED - Stetter, Joseph R. T1 - Development of new sensing materials using combinatorial and high-throughput experimentation T2 - Computational Methods for Sensor Material Selection N2 - New sensors with improved performance characteristics are needed for applications as diverse as bedside continuous monitoring, tracking of environmental pollutants, monitoring of food and water quality, monitoring of chemical processes, and safety in industrial, consumer, and automotive settings. Typical requirements in sensor improvement are selectivity, long-term stability, sensitivity, response time, reversibility, and reproducibility. Design of new sensing materials is the important cornerstone in the effort to develop new sensors. Often, sensing materials are too complex to predict their performance quantitatively in the design stage. Thus,combinatorial and high-throughput experimentation methodologies provide an opportunity to generate new required data to discover new sensing materials and/or to optimize existing material compositions. The goal of this chapter is to provide an overview of the key concepts of experimental development of sensing materials using combinatorial and high-throughput experimentation tools, and to promote additional fruitful interactions between computational scientists and experimentalists. Y1 - 2009 U6 - https://doi.org/10.1007/978-0-387-73715-7_7 SP - 151 EP - 166 PB - Springer CY - New York, NY [u.a.] ER - 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 - Lange, Ulrich A1 - Mirsky, Vladimir M. T1 - Separated analysis of bulk and contact resistance of conducting polymers: comparison of simultaneous 2- and 4-point measurements with impedance measurements T2 - Journal of Electroanalytical Chemistry N2 - Simultaneous measurements of conductive polymer by two-and four-point techniques were used for evaluation of the contact resistance for the polymer/metal interface. An experimental validation of this approach was performed for polypyrrole electrochemically deposited on gold electrodes. The dependence of contact resistance on the electrode potential versus reference electrode was measured. The results were compared with the corresponding dependence obtained from impedance spectroscopy. Both techniques provide almost identical data while the new approach is easier, faster and independent on selection of equivalent circuits. KW - Conducting polymer KW - Polypyrrole KW - Contact resistance KW - Simultaneous two KW - Four-point measurements Y1 - 2008 U6 - https://doi.org/10.1016/j.jelechem.2008.06.013 SN - 1572-6657 VL - 622 IS - 2 SP - 246 EP - 251 ER - TY - GEN A1 - Hodzhaoglu, Feyzim A1 - Kurniawan, Fredy A1 - Mirsky, Vladimir M. A1 - Nanev, Christo T1 - Gold nanoparticles induce protein crystallization T2 - Crystal Research and Technology N2 - Nucleation of protein crystals by gold nanoparticles was observed. Lysozyme and ferritin were used as model proteins. The effect was established with uncoated gold nanoparticles and with gold nanoparticles coated by 16-mercaptodecanoic acid. KW - gold nanoparticles KW - protein crystallization KW - nucleants KW - lysozyme KW - ferritin Y1 - 2008 U6 - https://doi.org/10.1002/crat.200811125 SN - 1521-4079 VL - 43 IS - 6 SP - 588 EP - 593 ER - TY - GEN A1 - Lange, Ulrich A1 - Roznyatovskaya, Nataliya V. A1 - Mirsky, Vladimir M. T1 - Conducting polymers in chemical sensors and arrays (invited review) T2 - Analytica Chimica Acta N2 - The review covers main applications of conducting polymers in chemical sensors and biosensors. The first part is focused on intrinsic and induced receptor properties of conducting polymers, such as pH sensitivity, sensitivity to inorganic ions and organic molecules as well as sensitivity to gases. Induced receptor properties can be also formed by molecularly imprinted polymerization or by immobilization of biological receptors. Immobilization strategies are reviewed in the second part. The third part is focused on applications of conducting polymers as transducers and includes usual optical (fluorescence, SPR, etc.) and electrical (conductometric, amperometric, potentiometric, etc.) transducing techniques as well as organic chemosensitive semiconductor devices. An assembly of stable sensing structures requires strong binding of conducting polymers to solid supports. These aspects are discussed in the next part. Finally, an application of combinatorial synthesis and high-throughput analysis to the development and optimization of sensing materials is described. KW - Conducting polymers KW - Chemical sensors KW - Electroactive polymers KW - Gas sensors KW - Combinatorial techniques KW - Electropolymerization KW - Sensor array Y1 - 2008 U6 - https://doi.org/10.1016/j.aca.2008.02.068 SN - 0003-2670 VL - 614 IS - 1 SP - 1 EP - 26 ER - TY - GEN A1 - Kurniawan, Fredy A1 - Tsakova, Vessela T. A1 - Mirsky, Vladimir M. T1 - Analytical applications of electrodes modified by gold nanoparticles: dopamine detection T2 - Journal of Nanoscience and Nanotechnology N2 - Dopamine oxidation was studied on modified gold (nano-Au) electrodes obtained by Layer-by-Layer deposition of gold nanoparticles and polyacrylic acid. A gradual loss of electrochemical activity for the dopamine oxidation reaction is observed at pH 7. Simultaneous SPR spectroscopy and cyclic voltammetry indicate the formation of an adsorbed layer on the electrode surface at this pH value. Investigations, performed through electrochemical and SPR measurements at pH 4, give evidence for a reversible process. At this pH value both dopamine oxidation and reduction current peaks show linear dependence on the dopamine concentration and may be used for analytical applications. The use of the nano-Au electrode allows resolving the peaks corresponding to ascorbic acid and to dopamine oxidation by 240 mV thus providing a high selectively for dopamine detection in the presence of ascorbic acid. The detection limit of this electrode for dopamine is below 4 microM in the presence of 1 mM ascorbic acid. The sensitivity normalized to the macroscopic electrode surface is about 10 mA cm(-2) mM(-1) at sweep rate of 10 V/s. KW - ascorbic acid KW - dopamine KW - electrochemical detection KW - gold nanoparticles KW - surface plasmon resonance Y1 - 2009 U6 - https://doi.org/10.1166/jnn.2009.SE13 SN - 1533-4880 SN - 1533-4899 VL - 9 IS - 4 SP - 2407 EP - 2412 ER - TY - GEN A1 - Boecker, Daniel A1 - Zybin, Alexander A1 - Niemax, Kay A1 - Grunwald, Christian A1 - Mirsky, Vladimir M. T1 - Noise reduction by multiple referencing in surface plasmon resonance imaging T2 - Review of Scientific Instruments N2 - The analytical performance of surface plasmon resonance imaging with charge coupled device detection can be improved significantly by splitting a macroscopic sensing surface into multiple microscopic neighboring sensing and referencing subareas. It is shown that such a multiple referencing reduces intensity fluctuations across the total sensing area and, therefore, improves the signal/noise (S/N)ratio proportional to the splitting factor. The approach is demonstrated by detection of biotin binding to a monolayer of streptavidin. An effective variation of the reflected intensity of about 10⁻⁴, which corresponds to the refraction index variation of 3 x 10⁻⁶, was detected with a S/N ratio about 10 without any temperature stabilization of the sensing area. Y1 - 2008 U6 - https://doi.org/10.1063/1.2888527 SN - 1527-2400 VL - 79 IS - 2 SP - 023110 ER - TY - CHAP A1 - Potyrailo, Radislav A. A1 - Mirsky, Vladimir M. ED - Potyrailo, Radislav A. ED - Mirsky, Vladimir M. T1 - Combinatorial methods for chemical and biological sensors: Outlook T2 - Combinatorial Methods for Chemical and Biological Sensors N2 - This chapter provides a summary of status of combinatorial development of materials for chemical and biological sensors and an outlook for the future developments. Y1 - 2009 SN - 978-0-387-73712-6 U6 - https://doi.org/10.1007/978-0-387-73713-3_21 SP - 483 EP - 489 PB - Springer CY - New York, NY [u.a.] ER - TY - CHAP A1 - Potyrailo, Radislav A. A1 - Mirsky, Vladimir M. ED - Potyrailo, Radislav A. ED - Mirsky, Vladimir M. T1 - Introduction to combinatorial methods for chemical and biological sensors T2 - Combinatorial Methods for Chemical and Biological Sensors N2 - Sensing materials play a critical role in advancing selectivity, response speed, and sensitivity of chemical and biological determinations in gases and liquids. The desirable capabilities of sensing materials originate from their numerous functional parameters, which can be tailored to meet specific sensing needs. By increasing the structural and functional complexity of sensing materials, the ability to rationally define the precise requirements that will result in desired materials properties becomes increasingly limited. Combinatorial experimentation methodologies impact all areas of sensing materials research including inorganic, organic, and biological sensing materials. Y1 - 2009 SN - 978-0-387-73712-6 U6 - https://doi.org/10.1007/978-0-387-73713-3_1 SP - 3 EP - 24 PB - Springer CY - New York, NY [u.a.] ER - TY - CHAP A1 - Mirsky, Vladimir M. ED - Potyrailo, Radislav A. ED - Mirsky, Vladimir M. T1 - Combinatorial development of chemosensitive conductive polymers T2 - Combinatorial Methods for Chemical and Biological Sensors N2 - Conductive polymers are established materials for development of chemical and biological sensors. Properties of these polymers are influenced by a number of different physical and chemical factors. Application of combinatorial and high-throughput techniques to development and optimization of chemo and biosensors is reviewed. Methods for addressable synthesis of conductive polymers and protocols for comprehensive description of chemosensitive properties are discussed. Y1 - 2009 SN - 978-0-387-73712-6 U6 - https://doi.org/10.1007/978-0-387-73713-3_13 SP - 315 EP - 330 PB - Springer CY - New York, NY [u.a.] ER - TY - GEN A1 - Potyrailo, Radislav A. A1 - Mirsky, Vladimir M. T1 - Combinatorial and high-throughput development of sensing materials: The first ten years T2 - Chemical Reviews Y1 - 2008 U6 - https://doi.org/10.1021/cr068127f SN - 0009-2665 SN - 1520-6890 VL - 108 SP - 770 EP - 813 ER - TY - GEN A1 - Zybin, Alexander A1 - Boecker, Daniel A1 - Mirsky, Vladimir M. A1 - Niemax, Kay T1 - Enhancement of the detection power of surface plasmon resonance measurements by optimization of the reflection angle T2 - Analytical Chemistry N2 - The detection limit of surface plasmon resonance (SPR) measurements has been improved by a factor of approximately 2-3.5 if the angle of incidence was near to the reflection minimum of the SPR resonance curve instead at the position of the steepest slope, the standard alignment in SPR imaging. The enhancement of the detection power, a result of signal-to-noise optimization, is demonstrated by applying a photodiode and a CCD camera for SPR detection. The experimental data are compared with data expected from theory. Y1 - 2007 U6 - https://doi.org/10.1021/ac070074u SN - 0003-2700 SN - 1520-6882 VL - 79 IS - 11 SP - 4233 EP - 4236 ER - TY - GEN A1 - Delaney, Tetyana L. A1 - Zimin, Denys A1 - Rahm, Michael A1 - Weiss, Dieter A1 - Wolfbeis, Otto S. A1 - Mirsky, Vladimir M. T1 - Capacitive detection in ultrathin chemosensors prepared by molecularly imprinted grafting photopolymerization T2 - Analytical Chemistry N2 - The usual applications of capacitive detection in chemo- and biosensors are based on changes in effective thickness of insulating layers due to adsorption of analyte onto receptors. Ultrathin chemosensors based on molecularly imprinted polymerization enable a realization of another capacitive approach that exploits changes in electrical capacitance due to modification of the dielectric constant of the polymer. Such chemosensors were prepared by photografted molecularly imprinted polymerization on the surface of gold electrodes. An adsorbed layer of hydrophobic photoinitiator (benzophenone) provided grafted polymerization on the surface of the alkanethiol-modified gold electrode. The chemosensors were characterized by cyclic voltammetry, impedance spectroscopy, and scanning electron and atomic force microscopy. Binding of analyte was detected by measurements of electrical capacitance. The results indicate a decrease of the dielectric constant of the polymer layer due to analyte binding up to 20%. Y1 - 2007 U6 - https://doi.org/10.1021/ac062143v SN - 0003-2700 SN - 1520-6882 VL - 79 IS - 8 SP - 3220 EP - 3225 ER - TY - CHAP A1 - Mirsky, Vladimir M. ED - Corain, Benedetto ED - Schmid, Günter ED - Toshima, Naoki T1 - Spreader-bar structures as molecular templates for electrochemical synthesis of nanoparticles T2 - Metal nanoclusters in catalysis and materials science: the issue of size-control Y1 - 2008 U6 - https://doi.org/10.1016/B978-044453057-8.50020-9 SP - 321 EP - 325 PB - Elsevier CY - Amsterdam ER - TY - GEN A1 - Hirsch, Thomas A1 - Shaporenko, Andrey A1 - Mirsky, Vladimir M. A1 - Zharnikov, Michael T1 - Monomolecular films of phthalocyanines: formation, characterisation and expelling by alkanethiols T2 - Langmuir N2 - Adsorption of aluminum-2,3-naphthalocyanine (Al-PC) onto gold (111) substrate from the pure and mixed (with alkanethiols) solutions of the target molecules in ethanol was studied. The resulting films were characterized by X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy. The adsorption from the pure solution resulted in formation of an Al-PC monolayer composed of the strongly inclined molecules. However, a presence of only one molar percent of a thiolated compound (alkanethiol) in the primary solution led to the complete expelling of the Al-PC molecules from the substrate and formation of a one-component alkylthiolate monolayer. The results indicate that an equilibrium formation of mixed monolayers of rodlike thiolated molecules and relatively large planar-geometry molecules, whose interaction with the metal surface is mainly provided by the π-electron system, is difficult to achieve or is in most cases even impossible under equilibrium conditions and requires an introduction of additional anchor moieties (e.g., thiols) into these molecules, as has been demonstrated by successful coadsorption of hexadecanethiol and thiolated tetraphenylporphyrin. Y1 - 2007 U6 - https://doi.org/10.1021/la0634239 SN - 0743-7463 SN - 1520-5827 VL - 23 IS - 8 SP - 4373 EP - 4377 ER - TY - GEN A1 - Cao, Limin A1 - Lin, Hong A1 - Mirsky, Vladimir M. T1 - DNA-based surface plasmon resonance biosensor for enrofloxacin T2 - Analytica Chimica Acta N2 - A DNA-based surface plasmon resonance biosensor for enrofloxacin was developed. Heating denatured DNA immobilized on the gold-coated glass surface was exploited. The immobilization was performed by a layer-by-layer co-deposition with a cationic polymer. The sensor performance was tested with real biological probes. Direct and simple determination of enrofloxacin in milk samples was demonstrated. The sensor response obeys Langmuir binding isotherm being almost linear until about 20 µg per mL. The detection limit in milk samples was estimated to be 3 µg per mL. KW - Surface plasmon resonance KW - Nucleic acid KW - Biosensor KW - Enrofloxacin KW - Fluoroquinolones KW - Layer-by-layer deposition Y1 - 2007 U6 - https://doi.org/10.1016/j.aca.2007.02.034 SN - 0003-2670 VL - 589 IS - 1 SP - 1 EP - 5 ER - TY - GEN A1 - Cao, Limin A1 - Lin, Hong A1 - Mirsky, Vladimir M. T1 - Detection of antibiotics in food: Extraction of fluoroquinolones by DNA T2 - Analytical and Bioanalytical Chemistry N2 - The ability of DNA to extract fluoroquinolones from model solutions and real probes of food was demonstrated and investigated quantitatively. The interaction between fluoroquinolones and different types of DNA was studied by equilibrium dialysis. The first application of this direct approach allowed us to determine binding constants and binding stoichiometries in different conditions. The binding of enrofloxacin to heat-denatured DNA (d-DNA) from herring sperm is pH- and magnesium-dependent; the highest fraction of bound drugs was found at pH 7 and a magnesium concentration of 0.5–1 mM. Results for three types of DNA: d-DNA, double-stranded DNA and single-stranded DNA were compared. The unwound DNA showed almost doubled binding constants and stoichiometries, thus indicating preferable interaction of enrofloxacin with single-strand regions of DNA. The binding of other fluoroquinolones (lomefloxacin, ciprofloxacin, norfloxacin, danofloxacin and sarafloxacin) with d-DNA is very similar to that of enrofloxacin: the binding constants are in the range from 0.94 × 105 to 2.40 × 105 M−1, and the stoichiometries range from 4.1 to 6.9 fluoroquinolone molecules per 100 DNA bases. The binding properties were quantitatively the same for extraction of fluoroquinolones from model aqueous solutions and from liquid food (milk). The results indicate the efficiency of DNA for selective extraction of fluoroquinolones from real samples for further analysis. This selective binding also allows us to consider DNA as a natural receptor for development of analytical techniques for fluoroquinolones. KW - Fluoroquinolone KW - DNAExtraction KW - Binding constant KW - Binding stoichiometry Y1 - 2007 U6 - https://doi.org/10.1007/s00216-007-1191-5 SN - 1618-2642 SN - 1618-2650 VL - 388 IS - 1 SP - 253 EP - 258 ER - TY - CHAP A1 - Vasjari, Majlinda A1 - Mirsky, Vladimir M. ED - Alegret, Salvador ED - Merkoci, Arben T1 - Chemoresistor for determination of mercury vapor T2 - Electrochemical Sensor Analysis N2 - This chapter presents a procedure to prepare and calibrate chemical sensor for mercury vapor and discusses application of the sensor for measurements of mercury vapor. The sensor is based on high affinity of gold to mercury and on chemoresistive properties of ultrathin gold layers: adsorption of mercury leads to increase in the surface resistance. However, this effect is not selective: similar changes are caused by adsorption of water vapor and sulfuric compounds. The use of monomolecular layer of alkylthiols as a filter excludes this interference completely. Sensor calibration is performed by thermoinjection of nanogram-amount of mercury quantitatively deposited by electrochemical reduction. It is found that the sensors display no sensitivity to such typical interferents of mercury chemoresistors based on uncoated gold as volatile thiols and water. Preliminary data demonstrate a possibility to measure Hg(0) even in aqueous solutions. Y1 - 2007 SN - 978-0-444-53053-0 U6 - https://doi.org/10.1016/S0166-526X(06)49058-9 SP - 105 EP - 109 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Mirsky, Vladimir M. A1 - Vasjari, Majlinda ED - Alegret, Salvador ED - Merkoci, Arben T1 - Chemical sensors for mercury vapour T2 - Electrochemical Sensor Analysis N2 - A number of analytical methods were developed for determination of elemental mercury. They include traditional analytical techniques, such as atomic adsorption spectroscopy (AAS), atomic fluorescence spectroscopy (AFS), and atomic emission spectroscopy (AES). Other analytical methods include neutron-activation analysis and laser photo-acoustic spectroscopy (detection limit about 5 μg/l). To increase sensitivity and selectivity of these methods, a preconcentration of mercury is widely performed. This can be realized by exploring high affinity of mercury to gold. Mercury and its volatile compounds can easily be adsorbed on gold at normal temperatures and can be released quantitatively upon heating. Hence, gold has been used as an adsorbent for the accumulation of mercury to a concentration sufficient for further spectroscopic analyses. The main disadvantage of mercury sensors based on bare gold layers is their poor selectivity and applications of such sensors for real probes and makes necessary a pre-treatment of probes. Mercury sensors based on thin gold layers require regular calibrations. In ideal cases, the calibration should be performed before each measurement. Therefore, a calibration technique should be compatible with design and concept of the mercury vapor sensor. Y1 - 2007 SN - 978-0-444-53053-0 U6 - https://doi.org/10.1016/S0166-526X(06)49012-7 SP - 235 EP - 251 PB - Elsevier CY - Amsterdam ER - TY - GEN A1 - Roznyatovskaya, Nataliya V. A1 - Laurinavichyute, Veronika K. A1 - Tsirlina, Galina A. A1 - Mirsky, Vladimir M. T1 - Electrochemistry and catalytic behavior of immobilized binuclear complexes of copper(II) and nickel(II) with Robson type ligand T2 - Journal of Solid State Electrochemistry N2 - Various systems containing immobilized binuclear copper(II) and nickel(II) complexes with Robson type ligand ([M2L]Cl2) are studied and compared in relation to catalysis of hydrogen peroxide reduction. Molecular complexes adsorbed on mercury and gold, crystalline complexes immobilized in the carbon paste electrode, and complex species entrapped into polyphenol-modified gold electrodes are considered. Electrocatalysis is assumed to result from the formation of H2O2–[M2L]Cl2 adduct, not from mediating redox transformations. Possible geometry of the formed reaction layers supporting adduct formation is discussed. KW - Binuclear copper macrocyclic complex KW - Cyclic voltammetry KW - Adsorption KW - Carbon paste electrodes KW - Electroreduction Y1 - 2007 U6 - https://doi.org/10.1007/s10008-006-0235-7 SN - 1432-8488 SN - 1433-0768 VL - 11 IS - 7 SP - 981 EP - 992 ER - TY - GEN A1 - Hao, Qingli A1 - Wang, Xin A1 - Lu, Lude A1 - Yang, Xujie A1 - Mirsky, Vladimir M. T1 - Electropolymerized multilayer conducting polymers with response to gaseous hydrogen chloride T2 - Macromolecular Rapid Communications N2 - A step-by-step ‘all-electrochemical’ approach has been presented to develop a multilayer structure of conducting polymers for gas sensors. The integrated structure includes a sensitive layer (polyaniline, PANI) and a conductive bridge consisting of poly(3,4-ethylenedioxythiophene) (PEDOT). Good sensitivity, stability, and response of the multilayer material to gaseous HCl indicate a possible application of conductive polymers to provide a binding of sensitive elements in sensors or other fields. The conducting multilayer material, Au/pATP/PANI/PEDOT, was synthesized electrochemically. Y1 - 2005 U6 - https://doi.org/10.1002/marc.200500114 SN - 1521-3927 VL - 26 IS - 13 SP - 1099 EP - 1103 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Kulikov, Valentin A1 - Wolfbeis, Otto S. T1 - Complete system for combinatorial synthesis and functional investigation of conductive polymers T2 - American Chemical Society PMSE Preprints N2 - Complete system for combinatorial electrochemical synthesis and functional characterization of combinatorial libraries formed by different polymers and polymeric structures will be presented. Control of electrical potential of single electrode groups consisting of four electrodes (designed for 4-point measurements ) on the array comprising 96 such electrode groups provides addressable electrochemical polymer synthesis on the defined electrodes. After polymerization, electrical characteristics of polymers or/and polymer/electrode contacts and influence of potential analytes on these characteristic are measured. Final data analysis provides complete analytically relevant information on the investigated thin polymer layers or multilayer polymer structures: absolute and relative sensitivity, response time, reversibility, reproducibility, regeneration kinetics, linearity or binding constant. Examples of applications for the development of gas-sensitive (co)polymers and optimization of their sensitive properties and polymer/metal contacts will be presented. Y1 - 2005 VL - 93 SP - 1053 ER - TY - GEN A1 - Hirsch, Thomas A1 - Zharnikov, Michael A1 - Shaporenko, Andrey A1 - Stahl, Joachim A1 - Weiss, Dieter A1 - Wolfbeis, Otto S. A1 - Mirsky, Vladimir M. T1 - Size-controlled electrochemical synthesis of metallic nanoparticles on molecular templates T2 - Angewandte Chemie International Edition N2 - Reduction on the spot: Planarly adsorbed thiolated porphyrin molecules (purple) incorporated in an insulating alkanethiol monolayer (blue) function as nanoelectrodes for the local reduction of metals (gray). This approach was applied for the in situ synthesis of nanoparticles of a predetermined size. Y1 - 2005 U6 - https://doi.org/10.1002/anie.200500912 SN - 1521-3773 VL - 44 IS - 41 SP - 6775 EP - 6778 ER - TY - GEN A1 - Zybin, Alexander A1 - Grunwald, Christian A1 - Mirsky, Vladimir M. A1 - Kuhlmann, Jürgen A1 - Wolfbeis, Otto S. A1 - Niemax, Kay T1 - Double-wavelength technique for surface plasmon resonance measurements: basic concept and applications for single sensors and two-dimensional sensor arrays T2 - Analytical Chemistry N2 - A new technique for on-line monitoring of analyte binding to sensor surfaces by surface plasmon resonance (SPR) detection is described. It is based on differential measurements using two wavelengths provided by two diode lasers. The technique is as simple and robust as the conventional SPR detection measuring the reflected radiation at fixed incidence angle, but it has the advantage of being nonsensitive to variations of the resonance width and providing essentially higher signal/noise ratios. The paper presents the first four channel prototype system for parallel 2D-monitoring at four different spots. One channel is always used as a reference to compensate temperature fluctuations and nonspecific adsorptions. Calibration with sucrose solutions revealed an absolute sensitivity of Δn ∼ 5 × 10-6. The new technique is tested with a biotin−streptavidin binding and with hybridization/denaturation of DNA. Biotin binding to a streptavidin monolayer is detected with a signal/noise ratio of about 5, which demonstrates the high potential of the new technique for applications in drug discovery. Applications to gene analysis are tested with short oligonucleotides of the sequences used for genotyping human hepatitis C viruses. A selective response to complementary oligonucleotides is observed. The high reproducibility in subsequent cycles of hybridization/denaturation (by formamide or by heating) points out potential applications of the technique in medical diagnostics, food industry, genomics, and proteomics too. Y1 - 2005 U6 - https://doi.org/10.1021/ac048156v SN - 0003-2700 SN - 1520-6882 VL - 77 IS - 8 SP - 2393 EP - 2399 ER - TY - CHAP A1 - Mirsky, Vladimir M. A1 - Kulikov, Valentin A1 - Hao, Qingli A1 - Wolfbeis, Otto S. T1 - Application of combinatorial electropolymerization to the development of chemical Sensors T2 - Combinatorial and artificial intelligence methods in materials science II, symposium held December 1 - 4, 2003, Boston, Massachusetts, U.S.A. N2 - Combinatorial electropolymerization with electrical addressing was realized on the array of 96 electrode groups, each from four electrodes. The polymer synthesis was combined with subsequent high-throughput investigation of analytical properties of synthesized polymers. Two-and four-point techniques were applied simultaneously to measure electrical properties of synthesized polymers and contact resistances between electrodes and polymers and modifications of these parameters on addition of analyte. The system was used for development of sensitive materials for detection of gaseous hydrogen chloride. Y1 - 2004 SN - 1-55899-742-3 U6 - https://doi.org/10.1557/PROC-804-JJ4.1 SP - 111 EP - 116 PB - Materials Research Society CY - Warrendale, Pa. ER - TY - GEN A1 - Kurniawan, Fredy A1 - Tsakova, Vessela T. A1 - Mirsky, Vladimir M. T1 - Gold nanoparticles in non-enzymatic electrochemical detection of sugars T2 - Electroanalysis N2 - A nonenzymatic electrochemical sensor for detection of sugars was prepared by layer-by-layer deposition of gold nanoparticles on thin gold electrodes. The deposition was optimized by using of surface plasmon resonance. Voltammetric investigation and impedance spectroscopy of the sensor was performed. Electrical currents caused by glucose on bare gold electrodes and on gold electrodes coated by immobilized gold nanoparticles were compared. The electrodes with nanoparticles display much higher current of glucose oxidation. The oxidation becomes blocked when the swept electrode potential exceeded +0.25 V, during the back scan an oxidation peak is observed again but at less positive potential. The magnitudes of these current peaks are linearly dependent on the glucose concentration; this dependence can be used as calibration for analytical applications. The limit of detection for glucose is below 0.5 mM, the sensitivity (normalized to the macroscopic electrode surface) is about 160 μA cm-2 mM-1. The sensor response is linear till at least 8 mM of glucose concentration. KW - Gold nanoparticles KW - Electrochemical KW - Glucose detection Y1 - 2006 U6 - https://doi.org/10.1002/elan.200603607 SN - 1521-4109 VL - 18 IS - 19-20 SP - 1937 EP - 1942 ER - TY - GEN A1 - Mirsky, Vladimir M. T1 - Neue Technologie angewandter Polymerforschung. Hundert mal schneller zu neuen Sensormaterialien T2 - Aktuelle Wochenschau : HighChem hautnah. Aktuelles aus der analytischen Chemie Y1 - 2005 VL - 48 SP - 98 EP - 99 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 - Zhi, Zheng-liang A1 - Drazan, Viktor A1 - Wolfbeis, Otto S. A1 - Mirsky, Vladimir M. T1 - Electrocatalytic activity of DNA on electrodes as an indication of hybridization T2 - Bioelectrochemistry N2 - Electron transfer between metal electrodes and ferro/ferricyanide is completely suppressed at low ionic concentration. We describe here a new phenomenon related to this reaction: an immobilisation of thiolated single-stranded DNA on gold electrodes retains this activity at low ionic strength up to the level corresponding to the high ionic strength. In contrast, a hybridisation of the complementary DNAwith the thiolated single-stranded DNA followed by a binding onto the electrodes, attenuated the electrocatalytic effect. These effects can be used for discrimination between single-stranded DNA and double-stranded DNA and for semi-quantitative measurement of complementary DNA in a sample. KW - DNA KW - DNA-sensor KW - Biosensor KW - Electrocatalysi KW - Hybridisation KW - Oligonucleotide KW - Gene analysis Y1 - 2006 U6 - https://doi.org/10.1016/j.bioelechem.2005.02.006 SN - 1567-5394 VL - 68 IS - 1 SP - 1 EP - 6 ER - TY - GEN A1 - Krondak, Martin A1 - Broncová, Gabriela A1 - Anikin, Sergey A1 - Merz, Andreas A1 - Mirsky, Vladimir M. T1 - Chemosensitive properties of poly-4,4'-dialkoxy2,2’-bipyrroles T2 - Journal of Solid State Electrochemistry N2 - Chemosensitive properties of 4,4′-dimethoxy-2,2′-bipyrrole and 4,4′-dibuthoxy-2,2′-bipyrrole were investigated. These new conductive polymers were polymerized by cyclic voltammetry on the platinum and gold interdigitated electrodes designed for 2- and 4-point measurement of lateral conductivity. Thus, obtained polymers demonstrated high sensitivity to HCl in the parts per million concentration range. Kinetics of the gaseous HCl influence on the ratios of conductivities measured by 2- and 4-point techniques was analyzed. Some response of the polymers conductance towards NH3, NO and oxygen was also observed, but with much lower sensitivity than towards HCl. In aqueous solutions, the polymer conductivity was pH dependent; in comparison with 4,4′-dibuthoxy-2,2′-bipyrrole, the conductivity range of the methoxy derivative was shifted to acidic range for about two pH units. A possibility to use the pH dependence for the development of enzymatic biosensors with pH transducing was demonstrated. KW - Conductive polymer KW - Sensor KW - Conductivity KW - HCI KW - Alkoxybipyrroles Y1 - 2006 U6 - https://doi.org/10.1007/s10008-005-0069-8 SN - 1432-8488 SN - 1433-0768 VL - 10 IS - 3 SP - 185 EP - 191 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Kulikov, Valentin A1 - Hao, Qingli A1 - Wolfbeis, Otto S. T1 - Multiparameter High Throughput Characterization of Combinatorial Chemical Microarrays of Chemosensitive Polymers T2 - Macromolecular Rapid Communications N2 - High throughput characterization of combinatorial libraries demands a compromise between completeness of the study and reasonable investigation time. This compromise can be found by the development of test protocols consisting of the minimal number of the most informative measurements. Multiparameter high throughput characterization of sensitive materials is described. The parameters include response time, regeneration time, reversibility, reproducibility, sensitivity, linearity. The approach was applied for characterization of conductometric gas-sensitive polymer materials. Chemical microarrays prepared by electrochemical synthesis of polymers on platinum electrodes. Y1 - 2004 U6 - https://doi.org/10.1002/marc.200300210 SN - 1521-3927 VL - 25 IS - 1 SP - 253 EP - 258 ER - TY - GEN A1 - Kulikov, Valentin A1 - Mirsky, Vladimir M. T1 - Equipment for combinatorial electrochemical polymerization and high-throughput investigation of electrical properties of the synthesized polymers T2 - Measurement Science and Technology N2 - The first automated system for combinatorial synthesis and high throughput investigation of electrical properties of conductive polymers is described. The equipment provides a polymerization of defined mixtures of monomers into a thin layer on the addressed electrodes of an electrode array followed by measurements of current–voltage characteristics. The electrodes have an interdigital configuration, specially designed for four-point measurements. A programmed addition of gases or liquids provides automated investigation of the influence of different substances on the synthesized polymers. The results of an experimental test of the system are presented. This equipment can be used for synthesis and electrical characterization of conductive polymers and multilayer polymer structures, for development of chemical sensors, organic electronic devices and other thin film functional structures. KW - elect ropolymerization KW - chemical sensors KW - biological sensors KW - organic semiconductors KW - combinatorial approach KW - high-throughput screening Y1 - 2004 U6 - https://doi.org/10.1088/0957-0233/15/1/007 SN - 1361-6501 SN - 0957-0233 VL - 15 IS - 1 SP - 49 EP - 54 ER -