@misc{LangeHirschMirskyetal., author = {Lange, Ulrich and Hirsch, Thomas and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Hydrogen sensor based on graphene - palladium nanocomposite}, series = {Electrochimica Acta}, volume = {56}, journal = {Electrochimica Acta}, number = {10}, issn = {0013-4686}, doi = {10.1016/j.electacta.2010.10.078}, pages = {3707 -- 3712}, abstract = {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.}, language = {en} } @misc{WolpertWolfbeisMirsky, author = {Wolpert, Benjamin and Wolfbeis, Otto S. and Mirsky, Vladimir M.}, title = {Gas sensing properties of electrically conductive Cu(I) compounds at elevated temperatures}, series = {Sensors and Actuators B: Chemical}, volume = {142}, journal = {Sensors and Actuators B: Chemical}, number = {2}, issn = {0925-4005}, doi = {10.1016/j.snb.2009.04.042}, pages = {446 -- 450}, abstract = {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.}, language = {en} } @misc{DelaneyZiminRahmetal., author = {Delaney, Tetyana L. and Zimin, Denys and Rahm, Michael and Weiss, Dieter and Wolfbeis, Otto S. and Mirsky, Vladimir M.}, title = {Capacitive detection in ultrathin chemosensors prepared by molecularly imprinted grafting photopolymerization}, series = {Analytical Chemistry}, volume = {79}, journal = {Analytical Chemistry}, number = {8}, issn = {0003-2700}, doi = {10.1021/ac062143v}, pages = {3220 -- 3225}, abstract = {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\%.}, language = {en} } @misc{MirskyKulikovWolfbeis, author = {Mirsky, Vladimir M. and Kulikov, Valentin and Wolfbeis, Otto S.}, title = {Complete system for combinatorial synthesis and functional investigation of conductive polymers}, series = {American Chemical Society PMSE Preprints}, volume = {93}, journal = {American Chemical Society PMSE Preprints}, pages = {1053}, abstract = {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.}, language = {en} } @misc{HirschZharnikovShaporenkoetal., author = {Hirsch, Thomas and Zharnikov, Michael and Shaporenko, Andrey and Stahl, Joachim and Weiss, Dieter and Wolfbeis, Otto S. and Mirsky, Vladimir M.}, title = {Size-controlled electrochemical synthesis of metallic nanoparticles on molecular templates}, series = {Angewandte Chemie International Edition}, volume = {44}, journal = {Angewandte Chemie International Edition}, number = {41}, issn = {1521-3773}, doi = {10.1002/anie.200500912}, pages = {6775 -- 6778}, abstract = {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.}, language = {en} } @misc{ZybinGrunwaldMirskyetal., author = {Zybin, Alexander and Grunwald, Christian and Mirsky, Vladimir M. and Kuhlmann, J{\"u}rgen and Wolfbeis, Otto S. and Niemax, Kay}, title = {Double-wavelength technique for surface plasmon resonance measurements: basic concept and applications for single sensors and two-dimensional sensor arrays}, series = {Analytical Chemistry}, volume = {77}, journal = {Analytical Chemistry}, number = {8}, issn = {0003-2700}, doi = {10.1021/ac048156v}, pages = {2393 -- 2399}, abstract = {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.}, language = {en} } @inproceedings{MirskyKulikovHaoetal., author = {Mirsky, Vladimir M. and Kulikov, Valentin and Hao, Qingli and Wolfbeis, Otto S.}, title = {Application of combinatorial electropolymerization to the development of chemical Sensors}, series = {Combinatorial and artificial intelligence methods in materials science II, symposium held December 1 - 4, 2003, Boston, Massachusetts, U.S.A.}, booktitle = {Combinatorial and artificial intelligence methods in materials science II, symposium held December 1 - 4, 2003, Boston, Massachusetts, U.S.A.}, publisher = {Materials Research Society}, address = {Warrendale, Pa.}, isbn = {1-55899-742-3}, doi = {10.1557/PROC-804-JJ4.1}, pages = {111 -- 116}, abstract = {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.}, language = {en} } @misc{SamoylovMirskyHaoetal., author = {Samoylov, Anton V. and Mirsky, Vladimir M. and Hao, Qingli and Swart, Claudia and Shirshov, Yuri M. and Wolfbeis, Otto S.}, title = {Nanometer-thick SPR sensor for gaseous HCl}, series = {Sensors and Actuators B: Chemical}, volume = {106}, journal = {Sensors and Actuators B: Chemical}, number = {1}, issn = {0925-4005}, doi = {10.1016/j.snb.2004.08.029}, pages = {369 -- 372}, abstract = {The optical properties of electrochemically polymerized N-methylaniline are changed in the presence of gaseous hydrogen chloride. This effect was used for preparation of chemical sensors with transduction based on surface plasmon resonance. The interaction of hydrogen chloride with a two nm layer of poly-(N-methylaniline) on gold leads to the shift of the surface plasmon resonance. The analysis of the resonance spectra demonstrates that the effect is caused by an increase of the imaginary component of the refractive index; a minor contribution is also provided by film condensation leading to an increase of the real component of the refractive index and a decrease in the thickness. The effect is selective and quasi-reversible. The concentration dependence of the gas effect obeys Langmuir's adsorption isotherm with a reciprocal value of the binding constant of 850 ± 160 ppm.}, language = {en} } @misc{ZhiDrazanWolfbeisetal., author = {Zhi, Zheng-liang and Drazan, Viktor and Wolfbeis, Otto S. and Mirsky, Vladimir M.}, title = {Electrocatalytic activity of DNA on electrodes as an indication of hybridization}, series = {Bioelectrochemistry}, volume = {68}, journal = {Bioelectrochemistry}, number = {1}, issn = {1567-5394}, doi = {10.1016/j.bioelechem.2005.02.006}, pages = {1 -- 6}, abstract = {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.}, language = {en} } @misc{KulikovMirskyDelaneyetal., author = {Kulikov, Valentin and Mirsky, Vladimir M. and Delaney, Tetyana L. and Donoval, Daniel and Koch, Alexander W. and Wolfbeis, Otto S.}, title = {High-throughput analysis of bulk and contact conductance of polymer layers prepared by combinatorial electropolymerization}, series = {Measurement Science and Technology}, volume = {16}, journal = {Measurement Science and Technology}, number = {1}, issn = {1361-6501}, doi = {10.1088/0957-0233/16/1/013}, pages = {95 -- 99}, abstract = {An approach for high-throughput analysis of bulk and contact conductance of polymer layers is described and evaluated. The approach, based on s24-technique (simultaneous two- and four-point conductance measurements), was realized as a high-throughput method and applied for investigation of conductive polymers on an array of interdigital platinum electrodes. Several examples demonstrate distinctive influence of combinatorially varied conditions of polymer synthesis (polymerization charge, content of copolymers) as well as chemical treatment of the synthesized polymers in bulk and contact resistance of metal/polymer/metal systems. The developed high-throughput s24-technique can be widely applied to material research for investigation of bulk and contact electrical properties.}, language = {en} } @misc{AndoSwartPringsheimetal., author = {Ando, Masanori and Swart, Claudia and Pringsheim, Erika and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Optical ozone sensing properties of poly(2-chloroaniline), poly(N-methylaniline) and polyaniline films}, series = {Sensors and Actuators B: Chemical}, volume = {108}, journal = {Sensors and Actuators B: Chemical}, number = {1-2}, issn = {0925-4005}, doi = {10.1016/j.snb.2004.12.083}, pages = {528 -- 534}, abstract = {The ozone-sensitive visible/near-IR absorbance changes of poly(2-chloroaniline) (P(2ClANI)), poly(N-methylaniline) (P(NMeANI)) and polyaniline (PANI) films were investigated. These three polymer films, which were assumed to be present partially in a protonated form and partially in a reduced form, were prepared by chemical oxidation of the monomers followed by treatment with the reducing agent disodium disulfite. The P(2ClANI) film was sensitive to ozone at concentrations of down to 2.5 ppm, but saturation of sensitivity started to appear above 50 ppm. By contrast, the PANI and P(NMeANI) films were sensitive to ozone in a concentration range of 50-100 ppm without showing saturation of sensitivity.}, language = {en} } @misc{AndoSwartPringsheimetal., author = {Ando, Masanori and Swart, Claudia and Pringsheim, Erika and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Ozone sensing properties of polyaniline derivatives}, series = {Chemical Sensors (Suppl. B)}, volume = {20}, journal = {Chemical Sensors (Suppl. B)}, pages = {534 -- 535}, language = {en} } @misc{ProdramidisHirschWolfbeisetal., author = {Prodramidis, Mamas I. and Hirsch, Thomas and Wolfbeis, Otto S. and Mirsky, Vladimir M.}, title = {Enantioselective chemosensors based on spreader-bar structures}, series = {Electroanalysis}, volume = {15}, journal = {Electroanalysis}, number = {22}, issn = {1521-4109}, doi = {10.1002/elan.200302756}, pages = {1795 -- 1798}, abstract = {Chiroselective binding sites have been created on thin gold films by application of the spreader-bar approach. Impedometric techniques and surface plasmon resonance were applied to detect binding. (R)-(+)-1,1 '-Binaphthyl-2,2 '-diol (R-BNOH) and (S)-(-)-1,1 '-binaphthyl-2,2'-diol (S-BNOH) were used as model analytes. The artificial receptors were prepared by co-adsorption of 16-mercaptohexadecane (matrix) with a thiol-modified chiral selector (template). The conjugates of d, l-thioctic acid and (R)-(+)- or (S)-(-)-1,1'-binaphthyl-2,2'-diamine were used as templates. Different concentration ratios of the matrix and template were tested. No chiral selectivity of surfaces formed by either the matrix or the template alone was observed. The use of alkylthiols shorter than 16-mercaptohexadecane led to the formation of surfaces with no chiral selectivity. The gold electrodes coated by the spreader-bar technique displayed an enantioselectivity of up to 4.76 or up to 2.55 as measured by the capacitive and SPR methods, espectively.}, language = {en} } @misc{MirskyKulikovHaoetal., author = {Mirsky, Vladimir M. and Kulikov, Valentin and Hao, Qingli and Wolfbeis, Otto S.}, title = {Multiparameter High Throughput Characterization of Combinatorial Chemical Microarrays of Chemosensitive Polymers}, series = {Macromolecular Rapid Communications}, volume = {25}, journal = {Macromolecular Rapid Communications}, number = {1}, issn = {1521-3927}, doi = {10.1002/marc.200300210}, pages = {253 -- 258}, abstract = {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.}, language = {en} } @misc{HirschKettenbergerWolfbeisetal., author = {Hirsch, Thomas and Kettenberger, Hubert and Wolfbeis, Otto S. and Mirsky, Vladimir M.}, title = {A simple strategy for preparation of sensor arrays: Nanostructured monolayers as recognition elements}, series = {Chemical Communications}, journal = {Chemical Communications}, number = {3}, issn = {1359-7345}, doi = {10.1039/b210554c}, pages = {432 -- 433}, abstract = {The spreader-bar approach is a simple method for producing a huge variety of receptors with different selectivities. A sensor-array consisting of five such receptors is presented. A pattern recognition provides selective detection of different purines and pyrimidines.}, language = {en} } @misc{PanasyukDelaneyMirskyWolfbeis, author = {Panasyuk-Delaney, Tanya and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Capacitive sensors based on photografted molecularly imprinted polymers}, series = {Biocybernetics and Biomedical Engineering}, volume = {21}, journal = {Biocybernetics and Biomedical Engineering}, number = {3}, issn = {0208-5216}, pages = {43 -- 54}, abstract = {The reversible chemosensors to creatinine and desmetryn based on artificial chemoreceptors are described. A grafted photopolymerization combined with a technique of molecular imprinting was used for the receptor layer preparation. After polymer deposition and intensive washing from templates, the electrodes were investigated by impedance spectrometry. Creatinine and desmetryn binding were detected as a decrease in the electrode capacitance. Sensor response to creatining was highly selective. No response to the addition of sodium chloride, creatine, urea or glucose were observed. The electrodes coated with the molecularly imprinted polymers selective to desmetryn displayed specific binding of this herbicide: only small capacitive effects were observed to addition of terbumeton or atrazine, while metribuzine displayed capacitance decrease similar to desmetryn.}, language = {en} } @misc{PanasyukDelaneyMirskyUlbrichtetal., author = {Panasyuk-Delaney, Tanya and Mirsky, Vladimir M. and Ulbricht, Mathias and Wolfbeis, Otto S.}, title = {Impedometric herbicide chemosensors based on molecularly imprinted polymers}, series = {Analytica Chimica Acta}, volume = {435}, journal = {Analytica Chimica Acta}, number = {1}, issn = {0003-2670}, doi = {10.1016/S0003-2670(00)01280-0}, pages = {157 -- 162}, abstract = {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.}, language = {en} } @inproceedings{WrobelRieplSchinkingeretal., author = {Wrobel, Nadia and Riepl, Michael and Schinkinger, Manfred and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Capacitive thin film biosensors for bacteriophages and nucleic acids}, series = {Proceedings, EMBEC '99, November 4 - 7, 1999, Vienna, Austria}, booktitle = {Proceedings, EMBEC '99, November 4 - 7, 1999, Vienna, Austria}, publisher = {IFMBE}, address = {Stevenage}, pages = {362 -- 363}, language = {en} } @misc{PanasyukDelaneyMirskyPiletskyetal., author = {Panasyuk-Delaney, Tanya and Mirsky, Vladimir M. and Piletsky, Sergey A. and Wolfbeis, Otto S.}, title = {Electropolymerized molecularly imprinted polymers as receptor layers in capacitive chemical sensors}, series = {Analytical Chemistry}, volume = {71}, journal = {Analytical Chemistry}, number = {20}, issn = {0003-2700}, doi = {10.1021/ac9903196}, pages = {4609 -- 4613}, abstract = {The first application of molecularly imprinted polymers to chemical sensors with capacitive detection is described. The sensitive layer was prepared by electropolymerization of phenol on gold electrodes in the presence of the template (phenylalanine). The insulating properties of the polymer layer were studied by electrochemical impedance spectroscopy. Electrical leakages through the polymer layer were suppressed by deposition of a self-assembled monolayer of mercaptophenol before polymerization and of alkanethiol after polymerization. At the final stage of sensor preparation, the template was removed. The multilayer system obtained displayed a decrease in electrical capacitance on addition of phenylalanine. Only a low response was observed toward other amino acids and phenol.}, language = {en} } @misc{BajariLindstedtRiepletal., author = {Bajari, Tarek M. and Lindstedt, Ken A. and Riepl, Michael and Mirsky, Vladimir M. and Nimpf, Johannes and Wolfbeis, Otto S. and Dresel, Hans A. and Bautz, Ekkehard K. F. and Schneider, Wolfgang Johann}, title = {A minimal binding domain of the low density lipoprotein receptor gene family}, series = {Biological Chemistry}, volume = {379}, journal = {Biological Chemistry}, number = {8-9}, issn = {1437-4315}, doi = {10.1515/bchm.1998.379.8-9.1053}, pages = {1053 -- 1062}, language = {en} } @inproceedings{MirskyRieplMassetal., author = {Mirsky, Vladimir M. and Riepl, Michael and Mass, Markus and Hirsch, T. and Schweiss, R. and Wolfbeis, Otto S.}, title = {Capacitive detection of analyte binding in thin film chemo- and biosensors}, series = {Solid State Chemical and Biochemical Sensors}, booktitle = {Solid State Chemical and Biochemical Sensors}, editor = {Vincenzini, Pietro and Dori, L.}, publisher = {Techna}, address = {Faenza}, isbn = {88-86538-27-8}, pages = {441 -- 448}, language = {en} } @misc{MirskyMassKrauseetal., author = {Mirsky, Vladimir M. and Mass, Markus and Krause, Christian and Wolfbeis, Otto S.}, title = {Capacitive approach to determine phospholipase A2 activity towards artificial and natural substrates}, series = {Analytical Chemistry}, volume = {70}, journal = {Analytical Chemistry}, number = {17}, issn = {0003-2700}, doi = {10.1021/ac980102w}, pages = {3674 -- 3678}, abstract = {A capacitive approach has been employed to develop a novel method to determine phospholipase activity. The sensing electrodes have a structure like Au/S(CH₂)₁₇CH₃/substrate/electrolyte. Hydrolysis of the substrate, mediated by phospholipase A₂, leads to the formation of water-soluble products from the insoluble substrate. This results in desorption of these products into aqueous phase and corresponding increase of the electrode capacitance. The requirement of high water solubility of the reaction products can be achieved in two ways. In the first, short-chain phospholipids are used as the substrate, in which case, water-soluble products are formed and no additional reagents are required to promote desorption of these products. The sensors prepared by this strategy provide sensitive qualitative detection of phospholipases. The second way is based on the use of a water-soluble acceptor (for example, β-cyclodextrin) to solubilize the products of hydrolysis. It allows semiquantitative detection of phospholipase activity toward long-chain natural substrates. The reaction kinetics for this case was found to be monoexponential and linearly dependent on the phospholipase concentration. The detection limit of this method, as tested with phospholipase A₂ from bee venom and soy bean lecithin as the substrate, is ∼0.5 ng/mL (500 μunits/mL).}, language = {en} } @misc{MirskyRieplWolfbeis, author = {Mirsky, Vladimir M. and Riepl, Michael and Wolfbeis, Otto S.}, title = {Capacitive monitoring of protein immobilization and antigen-antibody reaction on the monomolecular films of alkylthiols adsorbed on gold electrodes}, series = {Biosensors and Bioelectronics}, volume = {12}, journal = {Biosensors and Bioelectronics}, number = {9-10}, issn = {0956-5663}, doi = {10.1016/S0956-5663(97)00053-5}, pages = {977 -- 989}, abstract = {Self-assembled monolayers of omega-mercaptohexadecanoic acid and omega-mercaptohexadecylamine on gold electrodes are stable at neutral pH and display pure capacitive behavior at frequencies around 20 Hz. Different methods of covalent immobilization of proteins on these monolayers are compared. Various reagents including succinimides, thionylchloride, p-nitrophenol and carbodiimides were used to activate the carboxy groups of the adsorbed monolayer of omega-mercaptohexadecanoic acid. Glutaraldehyde, cyanuric chloride and phenylene diisocyanate were used to activate the amino groups of the monolayer of omega-mercaptohexadecylamine. The immobilization of albumin on the activated surface was studied by capacitive measurements. The N-hydroxysuccinimide and carbodiimide methods were identified as most suitable for protein immobilization in that they did not compromise the insulating properties of the alkylthiol layer and led to maximal increase of its dielectric thickness. These approaches were used for a layer-by-layer preparation of a capacitive immunosensor. Specifically, antibodies to human serum albumin were immobilized on the alkylthiol mono-layer. Binding of the antigen led to a decrease of the electrode capacitance. The detection limit of the immunosensor is as low as 15 nM (1 mg/l).}, language = {en} } @misc{MirskyHirschPanasyuketal., author = {Mirsky, Vladimir M. and Hirsch, Thomas and Panasyuk, Tatiana L. and Piletsky, Sergey A. and Wolfbeis, Otto S.}, title = {Two- and three-dimensional artificial chemoreceptors: molecular spreader-bar vs. molecular imprinting}, series = {Medical and Biological Engineering and Computing}, volume = {37}, journal = {Medical and Biological Engineering and Computing}, number = {suppl.2}, issn = {0140-0118}, pages = {344 -- 345}, language = {en} } @misc{MirskyHirschPiletskyetal., author = {Mirsky, Vladimir M. and Hirsch, Thomas and Piletsky, Sergey A. and Wolfbeis, Otto S.}, title = {A spreader-bar approach to molecular architecture: formation of stable artificial chemoreceptors}, series = {Angewandte Chemie International Edition}, volume = {38}, journal = {Angewandte Chemie International Edition}, number = {8}, issn = {1521-3773}, doi = {10.1002/(SICI)1521-3773(19990419)38:8<1108::AID-ANIE1108>3.0.CO;2-C}, pages = {1108 -- 1110}, abstract = {The destructive influence of lateral diffusion on nanostructured monolayers can be prevented by using the spreader-bar technique. This approach allows the formation of stable artificial receptors for barbituric acid by lateral structuring of a dodecanethiol monolayer with molecular spreader-bars from thiobarbituric acid without chemical polymerization (see schematic representation). The new technique may have applications in chemosensors, affinity chromatography, stereoselective catalysis, and molecular electronics.}, language = {en} } @misc{RieplMirskyNovotnyetal., author = {Riepl, Michael and Mirsky, Vladimir M. and Novotny, Ivan and Tvarozek, Vladimir and Rehacek, Vlastimil and Wolfbeis, Otto S.}, title = {Optimization of capacitive affinity sensors: drift suppression and signal amplification}, series = {Analytica Chimica Acta}, volume = {392}, journal = {Analytica Chimica Acta}, number = {1}, issn = {0003-2670}, doi = {10.1016/S0003-2670(99)00195-6}, pages = {77 -- 84}, abstract = {The detection limit of capacitive affinity sensors based on the gold-alkanethiol system can be improved by optimization of sensor preparation and by signal amplification. The dissociation of the gold-sulfur binding is often a critical point leading to operative errors of such sensors. The stability of self-assembled monolayers prepared with different thiols on gold electrodes in aqueous and organic solvents was studied by the capacitive technique. The results show that monolayers made of 16-mercaptohexadecanoic acid are stable in aqueous solution and can be hardly extracted from a gold surface by ethanol, methanol, or dioxane, while a considerable damage of self-assembled monolayers was observed due to incubation in chloroform or dimethylformamide. In contrast, self-assembled monolayers made from short-chain disulfides or thiols (such as 3,3′-dithio-bis(propionic acid N-hydroxysuccinimide ester) or 11-mercaptoundecanoic acid) displayed a poor stability in aqueous phase. Capacitive affinity sensors based on these short-chain thiols showed a considerable drift of the signal. The use of long-chain thiols resulted in a stable signal; it was applied to compare capacitive effects due to immobilization of different biological molecules and for preparation of different biosensors. The response of capacitive biosensors can be amplified by formation of a sandwich structure. This principle was illustrated by subsequent adsorption of polyclonal anti-HSA after binding of HSA with a sensor for HSA based on monoclonal antibodies.}, language = {en} } @misc{RieplMirskyWolfbeis, author = {Riepl, Michael and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Electrical control of alkanethiols self-assembly on a gold surface as an approach for preparation of microelectrode arrays}, series = {Microchimica Acta}, volume = {131}, journal = {Microchimica Acta}, number = {1}, issn = {0026-3672}, doi = {10.1007/s006040050006}, pages = {29 -- 34}, abstract = {It is shown by capacitive monitoring that the self-assembly of alkanethiols on gold electrodes and desorption of these self-assembled monolayers from the electrodes are controlled by the electrode potential. At neutral pH, chemical adsorption of alkanethiols was observed at an electrode potential of +300 mV vs SCE, but only physical adsorption was detected when the electrode potential was -1400 mV vs SCE. At electrode potentials between these values (-300 mV, -600 mV), chemical adsorption of alkanethiols occurred, but the alkanethiol monolayers were not stable in the absence of the alkanethiol in the bulk solution and were desorbed from the gold electrode. The desorption rate was higher at more negative electrode potentials. These results can be used in designing methods for electrically addressable immobilization of different receptors on (micro)electrode arrays. This has been demonstrated by deposition of two different types of alkanethiols onto a two-electrode array.}, language = {en} } @misc{SchweissMirskyWolfbeis, author = {Schweiß, R{\"u}diger and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Capacitive study of self-assembled alkylthiol monolayers: surface charge effects and kinetics of surfactants adsorption}, series = {Materials Science Forum}, volume = {287-288}, journal = {Materials Science Forum}, issn = {1662-9752}, doi = {10.4028/www.scientific.net/MSF.287-288.427}, pages = {427 -- 430}, language = {en} } @misc{AndoSwartPringsheimetal., author = {Ando, Masanori and Swart, Claudia and Pringsheim, Erika and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Optical ozone detection by use of polyaniline film}, series = {Solid State Ionics}, volume = {152-153}, journal = {Solid State Ionics}, issn = {0167-2738}, doi = {10.1016/S0167-2738(02)00338-7}, pages = {819 -- 822}, abstract = {We report on the optical ozone sensitivity of a polyaniline (PANI) film prepared on the inner wall of a polystyrene cuvette by chemical oxidation of aniline from aqueous solution. The PANI film showed changes of optical absorbance in the presence of 50-100 ppm ozone in air at room temperature. The absorbance change was largest at wavelengths in the range of 500-800 nm. The absorbance changes brought about by ozone was partially reversible after removal of ozone from the atmosphere. These results suggest that PANI is a potential material for optical ozone detection.}, language = {en} } @misc{PanasyukDelaneyMirskyWolfbeis, author = {Panasyuk-Delaney, Tanya and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Capacitive creatinine sensor based on molecularly imprinted polymer}, series = {Electroanalysis}, volume = {14}, journal = {Electroanalysis}, number = {3}, issn = {1521-4109}, doi = {10.1002/1521-4109(200202)14:3<221::AID-ELAN221>3.0.CO;2-Y}, pages = {221 -- 224}, abstract = {The first reversible chemosensor to creatinine based on artificial chemoreceptors is described. The receptor layer was prepared by molecularly imprinted photopolymerization of acrylamidomethylpropanesulfonic acid and methylenediacrylamide. The polymer layer was grafted onto the surface of gold electrodes coated with an alkanethiol monolayer. Creatinine binding was detected by a decrease in the electrode capacitance. The sensor response is reversible and highly selective: no response to addition of sodium chloride, creatine, urea or glucose were observed. The detection limit for creatinine is 10 μM which is optimal for medical applications.}, language = {en} } @misc{MirskyVasjariNovotnyetal., author = {Mirsky, Vladimir M. and Vasjari, Majlinda and Novotny, Ivan and Rehacek, Vlastimil and Tvarozek, Vladimir and Wolfbeis, Otto S.}, title = {Self-assembled monolayers as selective filters for chemical sensors}, series = {Nanotechnology}, volume = {13}, journal = {Nanotechnology}, number = {2}, issn = {0957-4484}, pages = {175 -- 178}, abstract = {The lateral electrical conductivity of gold layers with thickness in the nanometre range was found to decrease due to adsorption of mercury, water, iodine and sulphuric compounds onto the gold surface. A self-assembled monolayer of hexadecanethiol, deposited on the gold surface, blocked the effects of water and volatile sulphuric compounds on the lateral conductivity of the gold layers, but does not block the effects of iodine and mercury. The results indicate a selective permeability of hexadecanethiol monolayers for mercury vapour, thus providing a method for development of ultrathin filters for chemical sensors.}, language = {en} } @inproceedings{WuLinMirskyetal., author = {Wu, Meng and Lin, Zhihong and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Detection of DNA hybridization with surface plasmon resonance biosensor: comparison of immobilization of oligonucleotides by ssDNA and dsDNA}, series = {Proceedings, International Conference on Sensor Technology (ISTC 2001), 10 - 12 October 2001, Wuhan, China}, booktitle = {Proceedings, International Conference on Sensor Technology (ISTC 2001), 10 - 12 October 2001, Wuhan, China}, editor = {Zhou, Yikai}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {0-8194-4119-8}, doi = {10.1117/12.440180}, pages = {23 -- 26}, abstract = {In this research, a surface-plasmon resonance biosensor for nucleic acid detection was constructed, optimized and characterized. The kinetic response on hybridization was also studied. The biosensor was use as a platform for the study of the surface coverage control by single-strand or double-strand oligonucleotide immobilization. The dsDNA immobilization and offers a new way to surface coverage control for the nucleic acid biosensor construction.}, language = {en} } @misc{MirskyPanasyukDelaneyWolfbeis, author = {Mirsky, Vladimir M. and Panasyuk-Delaney, Tanya and Wolfbeis, Otto S.}, title = {Chemical sensors based on ultrathin membranes from molecularly imprinted polymers}, series = {Membrane \& cell biology}, volume = {18}, journal = {Membrane \& cell biology}, number = {6}, pages = {496 -- 501}, language = {en} } @inproceedings{LinWuRenetal., author = {Lin, Zhihong and Wu, Meng and Ren, Shu and Arbter, Michaela and Boehmer, Martin and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Study of single and dual NIR fluorescently labeled nucleic acid conjugates for nucleic acid detection}, series = {Proceedings, International Conference on Sensor Technology (ISTC 2001), 10 - 12 October 2001, Wuhan, China}, booktitle = {Proceedings, International Conference on Sensor Technology (ISTC 2001), 10 - 12 October 2001, Wuhan, China}, editor = {Zhou, Yikai}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {0-8194-4119-8}, doi = {10.1117/12.440165}, pages = {111 -- 114}, abstract = {In this research, a near-IR fluorescent labeled nucleic acid conjugate for the nucleic acid detection was synthesized, and characterized preliminarily for the detection of the nucleic acid. Th conjugate combines the molecular recognition properties of the oligonucleotides with the near-IR fluorescence label PR646. Both single- and dual- labeled conjugates were studied for their hybridization with the complementary nucleic acid. The dual labeled conjugate has indicated that the self-quenching effect exists in ssDNA form while the fluorescence increases greatly after hybridization with the complementary nucleic acids. The time-resolved fluorescence was also studied.}, language = {en} } @misc{MirskyRieplKrauseetal., author = {Mirsky, Vladimir M. and Riepl, Michael and Krause, Christian and Novotny, Ivan and Splonskowski, Markus and Rehacek, Vlastimil and Tvarozek, Vladimir and Hummel, Helmut and Wolfbeis, Otto S.}, title = {Thin film electrodes for capacitive chemo- and biosensors: an optimization of the electrodes geometry}, series = {Materials Science Forum}, volume = {287-288}, journal = {Materials Science Forum}, issn = {1662-9752}, doi = {10.4028/www.scientific.net/MSF.287-288.423}, pages = {423 -- 426}, language = {en} } @misc{MirskyWrobelRiepletal., author = {Mirsky, Vladimir M. and Wrobel, Nadia and Riepl, Michael and Hirsch, Thomas and Wolfbeis, Otto S.}, title = {Intelligente Nanostrukturen f{\"u}r Biosensoren und Sensor-Arrays}, series = {BioTec: Zeitschrift f{\"u}r Biotechnologie}, volume = {10}, journal = {BioTec: Zeitschrift f{\"u}r Biotechnologie}, issn = {0937-2725}, pages = {28 -- 32}, language = {de} } @misc{WolfbeisMirskyRiepl, author = {Wolfbeis, Otto S. and Mirsky, Vladimir M. and Riepl, Michael}, title = {Method for producing laterally organized structures on supporting surfaces}, language = {en} } @misc{RehacekNovotnyTvarozeketal., author = {Rehacek, Vlastimil and Novotny, Ivan and Tvarozek, Vladimir and Riepl, Michael and Hirsch, T. and Mass, Markus and Schweiss, R. and Mirsky, Vladimir M. and Wolfbeis, Otto S.}, title = {Capacitive detection in thin film chemical sensors and biosensors}, series = {Advanced Semiconductor Devices and Microsystems}, journal = {Advanced Semiconductor Devices and Microsystems}, editor = {Breza, Jura and Donoval, Daniel}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {0-7803-4909-1}, pages = {255 -- 258}, abstract = {Thin film electrode chips on silicon substrate have been realized and utilized in development of different chemo- and biosensors. These affinity sensors are based on capacitive transducing and their general structure is thin film Au/alkanethiol/receptor. Several applications of thin film gold electrodes in capacitive sensors are presented.}, language = {en} } @misc{AndoWolfbeisMirsky, author = {Ando, Masanori and Wolfbeis, Otto S. and Mirsky, Vladimir M.}, title = {Ozone detecting material and method for detecting ozone}, language = {en} }