@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{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} } @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{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{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{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{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{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} }