TY - JOUR A1 - Streffer, Katrin A1 - Kaatz, Helvi A1 - Bauer, Christian G. A1 - Makower, Alexander A1 - Schulmeister, Thomas A1 - Scheller, Frieder W. A1 - Peter, Martin G. A1 - Wollenberger, Ursula T1 - Application of a sensitive catechol detector for determination of tyrosinase inhibitors Y1 - 1998 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Lisdat, Fred A1 - Wollenberger, Ursula T1 - Application of electrically contacted enzymes for biosensors Y1 - 2005 SN - 3-527- 30690-0 ER - TY - JOUR A1 - Ozcelikay, Goksu A1 - Kurbanoglu, Sevinc A1 - Yarman, Aysu A1 - Scheller, Frieder W. A1 - Ozkan, Sibel A. T1 - Au-Pt nanoparticles based molecularly imprinted nanosensor for electrochemical detection of the lipopeptide antibiotic drug Daptomycin JF - Sensors and actuators : B, Chemical N2 - In this work, a novel electrochemical molecularly imprinted polymer (MIP) sensor for the detection of the lipopeptide antibiotic Daptomycin (DAP) is presented which integrates gold decorated platinum nanoparticles (Au-Pt NPs) into the nanocomposite film. The sensor was prepared by electropolymerization of o-phenylenediamine (o-PD) in the presence of DAP using cyclic voltammetry. Cyclic voltammetry and differential pulse voltammetry were applied to follow the changes in the MIP-layer related to rebinding and removal of the target DAP by using the redox marker [Fe(CN)(6)](3-/4-). Under optimized operational conditions, the MIP/Au-Pt NPs/ GCE nanosensor exhibits a linear response in the range of 1-20 pM towards DAP. The limit of detection and limit of quantification were determined to be 0.161pM +/- 0.012 and 0.489pM +/- 0.012, respectively. The sensitivity towards the antibiotics Vancomycin and Erythromycin and the amino acids glycine and tryptophan was below 7 percent as compared with DAP. Moreover, the nanosensor was also successfully used for the detection of DAP in deproteinated human serum samples. KW - molecularly imprinted polymer KW - Daptomycin KW - platinum nanoparticles KW - gold KW - nanoparticles KW - modified electrodes Y1 - 2020 U6 - https://doi.org/10.1016/j.snb.2020.128285 SN - 0925-4005 VL - 320 PB - Elsevier Science CY - Amsterdam ER - TY - JOUR A1 - Bauer, Christian G. A1 - Eremenko, A. V. A1 - Kühn, A. A1 - Kürzinger, K. A1 - Markower, Alexander A1 - Scheller, Frieder W. T1 - Automated amplifield flow immunoassay for cocaine Y1 - 1998 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Scheller, A. T1 - Bi-Enzymelektrode zur Messung von Sorbitol in pharmazeutischen Produkten Y1 - 1996 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Yarman, Aysu T1 - Bio vs. Mimetika in der Bioanalytik T1 - Bio vs. Mimetics in Bioanalysis: An Editorial BT - ein Editorial JF - Biochemie und analytische Biochemie N2 - Natürliche Evolution hat geschaffenBiopolymereauf der Basis von Aminosäuren undNukleotidezeigt hohe chemische Selektivität und katalytische Kraft. Die molekulare Erkennung durch Antikörper und die katalytische Umwandlung der Substratmoleküle durch Enzyme findet in sogenannten Paratopen oder katalytischen Zentren des Makromoleküls statt, die typischerweise 10-15 Aminosäuren umfassen. Die konzertierte Wechselwirkung zwischen den Reaktionspartnern führt zu Affinitäten bis zu nanomolaren Konzentrationen für die Antigenbindung und nähert sich einer Million Umsätze pro Sekunde anEnzym-katalysierte Reaktionen. N2 - Natural evolution has created biopolymers on the basis of amino acids and nucleotides showing high chemical selectivity and catalytic power. Molecular recognition by antibodies and catalytic conversion of the substrate molecules by enzymes take place in so called paratopes or catalytic centres of the macromolecule which comprise typically 10-15 amino acids. The concerted interaction between the reaction partners result in affinities down to nanomolar concentrations for the antigen binding and approaches one million turnovers per second in enzyme-catalyzed reactions. Nucleic acids bind complimentary single stranded nucleic acids by base pairing (hybridisation) with nanomolar affinities but also interact highly specific with proteins, e.g. transcription factors, and lowmolecular weight molecules and even with ions. Biomimetic binders and catalysts have been generated using “evolution in the test tube” of non-natural nucleotides or total chemical synthesis of (molecularly imprinted) polymers in order to substitute the biological pendants in bioanalysis. Y1 - 2015 SN - 2161-1009 VL - 4 IS - 2 ER - TY - JOUR A1 - Jetzschmann, Katharina J. A1 - Tank, Steffen A1 - Jagerszki, Gyula A1 - Gyurcsanyi, Robert E. A1 - Wollenberger, Ulla A1 - Scheller, Frieder W. T1 - Bio-Electrosynthesis of Vectorially Imprinted Polymer Nanofilms for Cytochrome P450cam JF - ChemElectroChem N2 - A new approach for synthesizing a vectorially imprinted polymer (VIP) is presented for the microbial cytochrome P450cam enzyme. A surface attached binding motif of a natural reaction partner of the target protein, putidaredoxin (Pdx), is the anchor to the underlying transducer. The 15 amino acid peptide anchor, which stems from the largest continuous amino acid chain within the binding site of Pdx was modified: (i) internal cysteines were replaced by serines to prevent disulfide bond formation; (ii) 2 ethylene glycol units were attached to the N-terminus as a spacer region; and (iii) an N-terminal cysteine was added to allow the immobilization on the gold electrode surface. Immobilization on GCE was achieved via an N-(1-pyrenyl)maleimide (NPM) cross-linker. In this way oriented immobilization of P450cam was accomplished by binding it to a peptide-modified gold or glassy carbon electrode (GCE) prior to the electrosynthesis of a polymer nanofilm around the immobilized target. This VIP nanofilm enabled reversible oriented docking of P450cam as it is indicated by the catalytic oxygen reduction via direct electron transfer between the enzyme and the underlying electrode. Catalysis of oxygen reduction by P450cam bound to the VIP-modified GCE was used to measure rebinding to the VIP. The mild coupling of an oxidoreductase with the electrode may be appropriate for realizing electrode-driven substrate conversion by instable P450 enzymes without the need of NADPH co-factor. KW - cytochrome P450 KW - direct electron transfer KW - electropolymerization KW - molecularly imprinted polymers KW - protein imprinting Y1 - 2019 U6 - https://doi.org/10.1002/celc.201801851 SN - 2196-0216 VL - 6 IS - 6 SP - 1818 EP - 1823 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Lehmann, Claudia A1 - Wollenberger, Ursula A1 - Brigelius-Flohé, Regina A1 - Scheller, Frieder W. T1 - Bioelectrocatalysis by a selenoenzyme Y1 - 1998 ER - TY - JOUR A1 - Bogdanovskaya, V. A. A1 - Fridman, Vadim A1 - Tarasevich, M. R. A1 - Scheller, Frieder W. T1 - Bioelectrocatalysis by immobilized peroxidase : the reaction mechanism and the possibility of electroanalytical detection of both inhibitors and activators of enzyme Y1 - 1994 ER - TY - JOUR A1 - Yarman, Aysu A1 - Nagel, Thomas A1 - Gajovic-Eichelmann, Nenad A1 - Fischer, Anna A1 - Wollenberger, Ursula A1 - Scheller, Frieder W. T1 - Bioelectrocatalysis by Microperoxidase-11 in a Multilayer Architecture of Chitosan Embedded Gold Nanoparticles JF - Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis N2 - We report on the redox behaviour of the microperoxidase-11 (MP-11) which has been electrostatically immobilized in a matrix of chitosan-embedded gold nanoparticles on the surface of a glassy carbon electrode. MP-11 contains a covalently bound heme c as the redox active group that exchanges electrons with the electrode via the gold nanoparticles. Electroactive surface concentration of MP-11 at high scan rate is between 350+/-50 pmol cm(-2), which reflects a multilayer process. The formal potential (E degrees') of MP-11 in the gold nanoparticles-chitosan film was estimated to be -(267.7+/-2.9) mV at pH 7.0. The heterogeneous electron transfer rate constant (k(s)) starts at 1.21 s(-1) and levels off at 6.45 s(-1) in the scan rate range from 0.1 to 2.0 V s(-1). Oxidation and reduction of MP-11 by hydrogen peroxide and superoxide, respectively have been coupled to the direct electron transfer of MP-11. KW - Microperoxidase KW - Direct electron transfer KW - Nanoparticles KW - Hydrogen peroxide KW - Superoxide KW - Bioelectrocatalysis Y1 - 2011 U6 - https://doi.org/10.1002/elan.201000535 SN - 1040-0397 VL - 23 IS - 3 SP - 611 EP - 618 PB - Wiley-Blackwell CY - Malden ER -