TY - GEN A1 - Klemm, Franziska A1 - Johnson, Richard A1 - Mirsky, Vladimir M. T1 - Binding of protein nanoparticles to immobilized receptors T2 - Sensors and Actuators B: Chemical N2 - The interaction of nanoparticles manufactured from human serum albumin (HSA) with different types of receptor surfaces was studied. Four different immobilization techniques were used to chemically link the receptors to the detector surfaces, namely: (i) a surface coated by monoclonal antibodies by a single step immobilization technique using carbodiimide, (ii) a surface coated by the same technique but using polyclonal antibodies, (iii) a surface coated by monoclonal antibodies immobilized through the sugar groups of antibodies and (iv) a surface coated by polyclonal antibodies immobilized by the same technique as in (iii). The results showed that there was almost no difference in the affinity of HSA in the molecular form to all of these surfaces. However, the binding behaviour of nanoparticles made from the same protein was quite different as successful nanoparticle binding was only observed when the surfaces were produced using method (ii). Y1 - 2015 U6 - https://doi.org/10.1016/j.snb.2014.10.135 SN - 0925-4005 VL - 208 SP - 616 EP - 621 ER - TY - PAT A1 - Wolfbeis, Otto S. A1 - Mirsky, Vladimir M. A1 - Riepl, Michael T1 - Method for producing laterally organized structures on supporting surfaces Y1 - 2002 ER - TY - PAT A1 - Ando, Masanori A1 - Wolfbeis, Otto S. A1 - Mirsky, Vladimir M. T1 - Ozone detecting material and method for detecting ozone Y1 - 2002 ER - TY - PAT A1 - Mirsky, Vladimir M. A1 - Lange, Ulrich T1 - Multielectrode chemoresistor Y1 - 2010 ER - 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 -