@article{LiuWollenbergerHalameketal.2005, author = {Liu, Songqin and Wollenberger, Ursula and Halamek, Jan and Leupold, Eik and St{\"o}cklein, Walter F. M. and Warsinke, Axel and Scheller, Frieder W.}, title = {Affinity interaction betwen phenylboronic acid-carrying self-assembled monolayers and FAD or HRP}, year = {2005}, abstract = {A method is provided for the recognition of glycated molecules based on their binding affinities to boronate- carrying monolayers. The affinity interaction of flavin adenine dinucleotide (FAD) and horseradish peroxidase (HRP) with phenylboronic acid monolayers on gold was investigated by using voltammetric and microgravimetric methods. Conjugates of 3-aminopherrylboronic acid and 3,3'-dithiodipropionic acid di(N-hydroxysuccinimide ester) or 11-mercaptoundecanoic acid were prepared and self-assembled on gold surfaces to generate monolayers. FAD is bound to this modified sur-face and recognized by a pair of redox peaks with a formal potential of -0.433 V in a 0.1 m phosphate buffer solution, pH 6.5. Upon addition of a sugar to the buffer, the bound FAD could be replaced, indicating that the binding is reversible. Voltammetric, mass measurements, and photometric activity assays show that the HRP can also be bound to the interface. This binding is reversible, and HRP can be replaced by sorbitol or removed in acidic solution. The effects of pH, incubation time, and concentration of H2O2 were studied by comparing the catalytic reduction of H2O2 in the presence of the electron-donor thionine. The catalytic current of the HRP-loaded electrode was proportional to HRP concentrations in the incubation solution in the range between 5 mu g mL(-1) and 0.4 mg mL(-1) with a linear slope of 3.34 mu A mL mg(-1) and a correlation coefficient of 0.9945}, language = {en} } @article{MakowerBarminMorzunovaetal.1997, author = {Makower, Alexander and Barmin, Anatoli V. and Morzunova, T. and Eremenko, Arkadi V. and Bier, Frank Fabian and Scheller, Frieder W.}, title = {Affinity enzymomoetric assay for detection of organophosphorus compounds}, year = {1997}, language = {en} } @article{StoellnerSchellerWarsinke2002, author = {Stoellner, Daniela and Scheller, Frieder W. and Warsinke, Axel}, title = {Activation of cellulose membranes with 1,1{\"i}-carbonyldiimidazole or 1-cyano-4-4-dimethylaminopyridinium tetrafluoroborate as a basis for the development of immunosensors}, year = {2002}, language = {en} } @article{SchellerSchmid2020, author = {Scheller, Frieder W. and Schmid, Rolf}, title = {A tribute to Isao Karube (1942-2020) and his influence on sensor science}, series = {Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica}, volume = {412}, journal = {Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica}, number = {28}, publisher = {Springer}, address = {Berlin}, issn = {1618-2642}, doi = {10.1007/s00216-020-02946-5}, pages = {7709 -- 7711}, year = {2020}, language = {en} } @article{BeissenhirtzSchellerLisdat2004, author = {Beissenhirtz, Moritz Karl and Scheller, Frieder W. and Lisdat, Fred}, title = {A superoxide sensor based on a multilayer cytochrome c electrode}, issn = {0003-2700}, year = {2004}, abstract = {A novel multilayer cytochrome c electrode for the quantification of superoxide radical concentrations is introduced. The electrode consists of alternating layers of cytochrome c and poly(aniline(sulfonic acid)) on a gold wire electrode. The formation of multilayer structures was proven by SPR experiments. Assemblies with 2-15 protein layers showed electrochemical communication with the gold electrode. For every additional layer, a substantial increase in electrochemically active cytochrome c (cyt. c) was found. For electrodes of more than 10 layers, the increase was more than 1 order of magnitude as compared to monolayer electrode systems. Thermodynamic and kinetic parameters of the electrodes were characterized. The mechanism of electron transfer within the multilayer assembly was studied, with results suggesting a protein-protein electron-transfer model. Electrodes of 2-15 layers were applied to the in vitro quantification of enzymatically generated superoxide, showing superior sensitivity as compared to a monolayer-based sensor. An electrode with 6 cyt. c/PASA layers showed the highest sensitivity of the systems studied, giving an increase in sensitivity of half an order of magnitude versus the that of the monolayer electrode. The stability of the system was optimized using thermal treatment, resulting in no loss in sensor signal or protein loading after 10 successive measurements or 2 days of storage}, language = {en} } @article{BierEhrentreichFoersterDoellingetal.1997, author = {Bier, Frank Fabian and Ehrentreich-F{\"o}rster, Eva and D{\"o}lling, R. and Eremenko, A. V. and Scheller, Frieder W.}, title = {A redox-label immunosensor on basis of a bi-enzyme electrode}, year = {1997}, language = {en} } @article{GajovicHabermuellerWarsinkeetal.1999, author = {Gajovic, Nenad and Haberm{\"u}ller, K. and Warsinke, Axel and Schuhmann, W. and Scheller, Frieder W.}, title = {A pyruvate oxidase electrode based on an electrochemically deposited redox polymer}, year = {1999}, language = {en} } @article{TellerHalamekMakoweretal.2006, author = {Teller, C. and Halamek, Jan and Makower, Alexander and Fournier, Didier and Schulze, H. and Scheller, Frieder W.}, title = {A piezoelectric sensor with propidium as a recognition element for cholinesterases}, doi = {10.1016/j.snb.2005.02.053}, year = {2006}, abstract = {A piezoelectric biosensor has been developed on the basis of the reversible acetylcholinesterase (AChE) inhibitor propidium. The propidium cation was bound to a 11-mercaptoundecanoic acid monolayer on gold-coated quartz crystals. The immobilization was done via activation of carboxyl groups by 1,3-dicyclohexylcarbodiimide (DCC). Different types of cholinesterases (acetyl- and butyryl-ChE) from different origins were tested for their binding ability towards the immobilized propidium. Binding Studies were performed in a flow system, Furthermore, catalytically active and organophosphate-inhibited enzyme were compared re-aiding their binding capability. The binding constants were derived by using an one to one binding model and a refined model also including rebinding effects. It was shown that organophosphorylation of the active site hardly influences the affinity of AChE towards propidium. Furthermore the propidium-based biosensor provides equal sensitivity as compared with piezolelectric sensors with immobilized paraoxon- an active site ligand of AChE. (c) 2005 Elsevier B.V. All rights reserved}, language = {en} } @article{GajovicWarsinkeScheller1995, author = {Gajovic, Nenad and Warsinke, Axel and Scheller, Frieder W.}, title = {A novel multienzyme electrode for the determination of citrate}, year = {1995}, language = {en} } @article{SongBierScheller1995, author = {Song, Min Ik and Bier, Frank Fabian and Scheller, Frieder W.}, title = {A method to detect superoxide radicals using teflon membrane and superoxide dismutase}, year = {1995}, language = {en} }