TY - JOUR A1 - Stöllner, Daniela A1 - Stöcklein, Walter F. M. A1 - Scheller, Frieder W. A1 - Warsinke, Axel T1 - Membrane-immobilized haptoglobin as affinity matrix for a hemoglobin-A1c-immunosensor Y1 - 2002 ER - TY - JOUR A1 - Sigolaeva, L. V. A1 - Markower, Alexander A1 - Eremenko, A. V. A1 - Makhaeva, G. F. A1 - Malygin, V. V. A1 - Kurochkin, I. N. A1 - Scheller, Frieder W. T1 - Bioelectrochemical anaysis of neuropathy targes esterase activity in blood Y1 - 2001 ER - TY - JOUR A1 - Rose, Andreas A1 - Pfeiffer, Dorothea A1 - Scheller, Frieder W. A1 - Wollenberger, Ursula T1 - Quinoprotein glucose dehydrogenasemodified thick-film electrodes for the amperometric detection of phenolic compounds in flow injection analysis Y1 - 2001 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Wollenberger, Ursula A1 - Warsinke, Axel A1 - Lisdat, Fred T1 - Research and development in biosensors Y1 - 2001 ER - TY - JOUR A1 - Lisdat, Fred A1 - Utepbergenov, D. A1 - Haseloff, R. F. A1 - Blasig, Ingolf E. A1 - Stöcklein, Walter F. M. A1 - Scheller, Frieder W. A1 - Brigelius-Flohé, Regina T1 - An optical method for the detection of oxidative stress using protein-RNA interaction Y1 - 2001 ER - TY - JOUR A1 - Hock, Bertold A1 - Scheller, Frieder W. T1 - Conclusions and outlook Y1 - 2001 ER - TY - JOUR A1 - Ignatov, S. A1 - Ge, Bixia A1 - Scheller, Frieder W. A1 - Lisdat, Fred T1 - Detection of the antioxidant activity detection of flavonoids by using superoxide sensor Y1 - 2001 SN - 1-58603-164-3 ER - TY - JOUR A1 - Lehmann, Claudia A1 - Wollenberger, Ursula A1 - Brigelius-Flohé, Regina A1 - Scheller, Frieder W. T1 - Modified gold electrodes for electrochemical studies of the reaction phospholipid hydroperoxide glutathione peroxidas with glutathione and glutathione disulfide Y1 - 2001 ER - TY - JOUR A1 - Lisdat, Fred A1 - Ge, Bixia A1 - Meyerhoff, M. E. A1 - Scheller, Frieder W. T1 - Signal chains with cytochromes at SAM modified gold electrodes Y1 - 2001 ER - TY - JOUR A1 - Lisdat, Fred A1 - Ge, Bixia A1 - Krause, B. A1 - Ehrlich, A. A1 - Bienert, H. A1 - Scheller, Frieder W. T1 - Nucleic acid-promoted electron transfer to cytochrome c Y1 - 2001 ER - TY - JOUR A1 - Scheller, Frieder W. T1 - Biosensoren auf dem Weg zur Biochip-Technologie Y1 - 2001 UR - http://bisc.ch/de/focus_bioelektronik_1_d.pdf ER - TY - JOUR A1 - Scheller, Frieder W. T1 - Biomoleküle als Reporter in der Analytik : keine Forschung im Elfenbeinturm Y1 - 2001 ER - TY - JOUR A1 - Lisdat, Fred A1 - Scheller, Frieder W. T1 - Technical principles. Electrodes Y1 - 2000 SN - 90-5702-447-7 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Pfeiffer, Dorothea T1 - Biosensor-Technologie in der Medizin und den Biowissenschaften Y1 - 2000 ER - TY - JOUR A1 - Fridman, Vadim A1 - Wollenberger, Ursula A1 - Bogdanovskaya, V. A. A1 - Lisdat, Fred A1 - Ruzgas, T. A1 - Lindgren, A. A1 - Gorton, Lo A1 - Scheller, Frieder W. T1 - Electrochemical investigation of cellobiose oxidation by cellobiose dehydrogenase in the presence of cytochrome c as mediator Y1 - 2000 ER - TY - JOUR A1 - Makower, Alexander A1 - Barmin, Anatoli V. A1 - Scheller, Frieder W. T1 - Eine neue Methode zur hochempfindlichen Analyse von Pestiziden Y1 - 2000 ER - TY - JOUR A1 - Warsinke, Axel A1 - Benkert, Alexander A1 - Scheller, Frieder W. T1 - Electrochemical immunoassays Y1 - 2000 ER - TY - JOUR A1 - Gajovic, Nenad A1 - Binyamin, Gary A1 - Warsinke, Axel A1 - Scheller, Frieder W. A1 - Heller, A. T1 - Operation of a miniature redox hydrogel-based pyruvate sensor in undiluted deoxygenated calf serum Y1 - 2000 ER - TY - JOUR A1 - Lei, Chenghong A1 - Wollenberger, Ursula A1 - Scheller, Frieder W. T1 - Clay based direct electrochemistry of myoglobin Y1 - 2000 ER - TY - JOUR A1 - Lei, Chenghong A1 - Wollenberger, Ursula A1 - Jung, Christiane A1 - Scheller, Frieder W. T1 - Clay-bridged electron transfer between cytochrome P450(cam) and electrode Y1 - 2000 ER - TY - JOUR A1 - Lisdat, Fred A1 - Scheller, Frieder W. T1 - Principles of sensorial radical detection - a minireview Y1 - 2000 ER - TY - JOUR A1 - Chen, Ziping A1 - Warsinke, Axel A1 - Gajovic, Nenad A1 - Große, St. A1 - Hu, J. A1 - Kleber, H.-P. A1 - Scheller, Frieder W. T1 - A D-carnitine dehydrogenase electrode for the assessment of enantiomeric purity of L-carnitine preparations Y1 - 2000 ER - TY - JOUR A1 - Scheller, Frieder W. T1 - Biomolekulare Erkennungssysteme für die Biochemische Analytik Y1 - 2000 ER - TY - JOUR A1 - Scheller, Frieder W. T1 - Biosensor-Stabilität Y1 - 2000 ER - TY - JOUR A1 - Lisdat, Fred A1 - Ge, Bixia A1 - Stöcklein, Walter F. M. A1 - Scheller, Frieder W. A1 - Meyer, T. T1 - Electrochemical behaviour and nitric oxides interaction of immobilised cytochrome c from Rhodocyclus gelatinosus Y1 - 2000 ER - TY - JOUR A1 - Chen, Jian A1 - Wollenberger, Ursula A1 - Lisdat, Fred A1 - Ge, Bixia A1 - Scheller, Frieder W. T1 - Superoxide sensor based on hemin modified electrode Y1 - 2000 ER - TY - JOUR A1 - Ju, Huangxian A1 - Liu, Songqin A1 - Ge, Bixia A1 - Lisdat, Fred A1 - Scheller, Frieder W. T1 - Electrochemistry of cytochrome c immobilized on colloidal gold modified carbon paste electrodes and its electrocatalytic activity Y1 - 2000 ER - TY - JOUR A1 - Stöcklein, Walter F. M. A1 - Rohde, M. A1 - Scharte, Gudrun A1 - Behrsing, Olaf A1 - Warsinke, Axel A1 - Micheel, Burkhard A1 - Scheller, Frieder W. T1 - Sensitive detection of triazine and phenylurea pesticides in pure organic solvent by enzyme linked immunsorbent assay (ELISA): stabilities, solubilities and sensitives Y1 - 2000 ER - TY - JOUR A1 - Scheller, Frieder W. T1 - Deutliche Signale setzen [Leitartikel] Y1 - 1999 ER - TY - JOUR A1 - Huang, T. A1 - Warsinke, Axel A1 - Koroljova-Skorobogatko, O. V. A1 - Makower, Alexander A1 - Kuwana, T. A1 - Scheller, Frieder W. T1 - A bienzyme carbon paste electrode for the sensitive detection of NADPH and the measurement of glucose-6- phosphate dehydrogenase Y1 - 1999 ER - TY - JOUR A1 - Lisdat, Fred A1 - Ge, Bixia A1 - Scheller, Frieder W. T1 - Oligonucleotide-modified electrodes for fast electron transfer to cytochrome c Y1 - 1999 ER - TY - JOUR A1 - Lisdat, Fred A1 - Ge, Bixia A1 - Ehrentreich-Förster, Eva A1 - Reszka, R. A1 - Scheller, Frieder W. T1 - SOD activity measurement using cytochrome c modified electrode Y1 - 1999 ER - TY - JOUR A1 - Gajovic, Nenad A1 - Warsinke, Axel A1 - Huang, T. A1 - Schulmeister, Thomas A1 - Scheller, Frieder W. T1 - Characterization and mathematical modelling of a novel bienzyme electrode for L-malate with cofactor recycling Y1 - 1999 ER - TY - JOUR A1 - Bauer, Christian G. A1 - Kühn, A. A1 - Gajovic, Nenad A1 - Skorobogatko, O. V. A1 - Holt, P. J. A1 - Bruce, N. C. A1 - Makower, Alexander A1 - Lowe, Ch. R. A1 - Scheller, Frieder W. T1 - New enzymen sensors for morphine and codeine based on morphine dehydrogenase and laccase Y1 - 1999 ER - TY - JOUR A1 - Kleinjung, Frank A1 - Ehrentreich-Förster, Eva A1 - Scheller, Frieder W. T1 - Changing functionality of surfaces by directed self-assembly using oligonucleotides - the oligo-tag Y1 - 1999 ER - TY - JOUR A1 - Barmin, Anatoli V. A1 - Eremenko, Arkadi V. A1 - Osipova, T. A1 - Kurochkin, Iliya A1 - Makower, Alexander A1 - Scheller, Frieder W. T1 - Affinyi fermentometrischeskii analis ingibitorov cholinestarasi Y1 - 1999 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Jin, Wen A1 - Ehrentreich-Förster, Eva A1 - Ge, Bixia A1 - Lisdat, Fred A1 - Büttemeyer, R. A1 - Wollenberger, Ursula T1 - Cytochrome c based superoxide sensor for in vivo application Y1 - 1999 ER - TY - JOUR A1 - Lei, Chenghong A1 - Lisdat, Fred A1 - Wollenberger, Ursula A1 - Scheller, Frieder W. T1 - Cytochrome c : Clay-modified electrode Y1 - 1999 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 - Stojanovic, Zorica A1 - Erdossy, Julia A1 - Keltai, Katalin A1 - Scheller, Frieder W. A1 - Gyurcsanyi, Robert E. T1 - Electrosynthesized molecularly imprinted polyscopoletin nanofilms for human serum albumin detection JF - Analytica chimica acta : an international journal devoted to all branches of analytical chemistry N2 - Molecularly imprinted polymers (MIPs) rendered selective solely by the imprinting with protein templates lacking of distinctive properties to facilitate strong target-MIP interaction are likely to exhibit medium to low template binding affinities. While this prohibits the use of such MIPs for applications requiring the assessment of very low template concentrations, their implementation for the quantification of high-abundance proteins seems to have a clear niche in the analytical practice. We investigated this opportunity by developing a polyscopoletin-based MIP nanofilm for the electrochemical determination of elevated human serum albumin (HSA) in urine. As reference for a low abundance protein ferritin-MIPs were also prepared by the same procedure. Under optimal conditions, the imprinted sensors gave a linear response to HSA in the concentration range of 20-100 mg/dm(3), and to ferritin in the range of 120-360 mg/dm(3). While as expected the obtained limit of detection was not sufficient to determine endogenous ferritin in plasma, the HSA-sensor was successfully employed to analyse urine samples of patients with albuminuria. The results suggest that MIP-based sensors may be applicable for quantifying high abundance proteins in a clinical setting. (c) 2017 Elsevier B.V. All rights reserved. KW - Human serum albumin KW - Ferritin KW - Molecularly imprinted polymer KW - Scopoletin KW - Urine Y1 - 2017 U6 - https://doi.org/10.1016/j.aca.2017.04.043 SN - 0003-2670 SN - 1873-4324 VL - 977 SP - 1 EP - 9 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bognár, Zsófia A1 - Supala, Eszter A1 - Yarman, Aysu A1 - Zhang, Xiaorong A1 - Bier, Frank Fabian A1 - Scheller, Frieder W. A1 - Gyurcsanyi, Róbert E. T1 - Peptide epitope-imprinted polymer microarrays for selective protein recognition BT - application for SARS-CoV-2 RBD protein JF - Chemical science / RSC, Royal Society of Chemistry N2 - We introduce a practically generic approach for the generation of epitope-imprinted polymer-based microarrays for protein recognition on surface plasmon resonance imaging (SPRi) chips. The SPRi platform allows the subsequent rapid screening of target binding kinetics in a multiplexed and label-free manner. The versatility of such microarrays, both as synthetic and screening platform, is demonstrated through developing highly affine molecularly imprinted polymers (MIPs) for the recognition of the receptor binding domain (RBD) of SARS-CoV-2 spike protein. A characteristic nonapeptide GFNCYFPLQ from the RBD and other control peptides were microspotted onto gold SPRi chips followed by the electrosynthesis of a polyscopoletin nanofilm to generate in one step MIP arrays. A single chip screening of essential synthesis parameters, including the surface density of the template peptide and its sequence led to MIPs with dissociation constants (K-D) in the lower nanomolar range for RBD, which exceeds the affinity of RBD for its natural target, angiotensin-convertase 2 enzyme. Remarkably, the same MIPs bound SARS-CoV-2 virus like particles with even higher affinity along with excellent discrimination of influenza A (H3N2) virus. While MIPs prepared with a truncated heptapeptide template GFNCYFP showed only a slightly decreased affinity for RBD, a single mismatch in the amino acid sequence of the template, i.e. the substitution of the central cysteine with a serine, fully suppressed the RBD binding. Y1 - 2021 U6 - https://doi.org/10.1039/d1sc04502d SN - 2041-6539 VL - 13 IS - 5 SP - 1263 EP - 1269 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Tanne, Johannes A1 - Jeoung, Jae-Hun A1 - Peng, Lei A1 - Yarman, Aysu A1 - Dietzel, Birgit A1 - Schulz, Burkhard A1 - Schad, Daniel A1 - Dobbek, Holger A1 - Wollenberger, Ursula A1 - Bier, Frank Fabian A1 - Scheller, Frieder W. T1 - Direct Electron Transfer and Bioelectrocatalysis by a Hexameric, Heme Protein at Nanostructured Electrodes JF - Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis N2 - A nanohybrid consisting of poly(3-aminobenzenesulfonic acid-co-aniline) and multiwalled carbon nanotubes [MWCNT-P(ABS-A)]) on a gold electrode was used to immobilize the hexameric tyrosine-coordinated heme protein (HTHP). The enzyme showed direct electron transfer between the heme group of the protein and the nanostructured surface. Desorption of the noncovalently bound heme from the protein could be excluded by control measurements with adsorbed hemin on aminohexanthiol-modified electrodes. The nanostructuring and the optimised charge characteristics resulted in a higher protein coverage as compared with MUA/MU modified electrodes. The adsorbed enzyme shows catalytic activity for the cathodic H2O2 reduction and oxidation of NADH. KW - HTHP KW - Nanohybrid KW - Poylaniline KW - Multiwalled carbon nanotube Y1 - 2015 U6 - https://doi.org/10.1002/elan.201500231 SN - 1040-0397 SN - 1521-4109 VL - 27 IS - 10 SP - 2262 EP - 2267 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Kleinjung, Frank A1 - Bier, Frank Fabian A1 - Markower, Alexander A1 - Neumann, Barbara A1 - Wollenberger, Ursula A1 - Kurochkin, Iliya N. A1 - Eremenko, Arkadi V. A1 - Barmin, Anatoli V. A1 - Klußmann, Sven A1 - Fürste, Jens-Peter A1 - Erdmann, Volker A. A1 - Mansuy, D. T1 - New recognition elements in biosensing Y1 - 1998 ER - TY - JOUR A1 - Yarman, Aysu A1 - Kurbanoğlu, Sevinç A1 - Zebger, Ingo A1 - Scheller, Frieder W. T1 - Simple and robust BT - the claims of protein sensing by molecularly imprinted polymers JF - Sensors and actuators : B, Chemical : an international journal devoted to research and development of chemical transducers N2 - A spectrum of 7562 publications on Molecularly Imprinted Polymers (MIPs) has been presented in literature within the last ten years (Scopus, September 7, 2020). Around 10 % of the papers published on MIPs describe the recognition of proteins. The straightforward synthesis of MIPs is a significant advantage as compared with the preparation of enzymes or antibodies. MIPs have been synthesized from only one up to six functional monomers while proteins are made up of 20 natural amino acids. Furthermore, they can be synthesized against structures of low immunogenicity and allow multi-analyte measurements via multi-target synthesis. Electrochemical methods allow simple polymer synthesis, removal of the template and readout. Among the different sensor configurations electrochemical MIP-sensors provide the broadest spectrum of protein analytes. The sensitivity of MIP-sensors is sufficiently high for biomarkers in the sub-nanomolar region, nevertheless the cross-reactivity of highly abundant proteins in human serum is still a challenge. MIPs for proteins offer innovative tools not only for clinical and environmental analysis, but also for bioimaging, therapy and protein engineering. KW - Molecularly imprinted polymer KW - Plastibodies KW - Functional scaffolds KW - Biomimetic sensors KW - Proteins Y1 - 2021 U6 - https://doi.org/10.1016/j.snb.2020.129369 SN - 0925-4005 SN - 1873-3077 VL - 330 PB - Elsevier Science CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Caserta, Giorgio A1 - Zhang, Xiaorong A1 - Yarman, Aysu A1 - Supala, Eszter A1 - Wollenberger, Ulla A1 - Gyurcsányi, Róbert E. A1 - Zebger, Ingo A1 - Scheller, Frieder W. T1 - Insights in electrosynthesis, target binding, and stability of peptide-imprinted polymer nanofilms JF - Electrochimica acta : the journal of the International Society of Electrochemistry (ISE) N2 - Molecularly imprinted polymer (MIP) nanofilms have been successfully implemented for the recognition of different target molecules: however, the underlying mechanistic details remained vague. This paper provides new insights in the preparation and binding mechanism of electrosynthesized peptide-imprinted polymer nanofilms for selective recognition of the terminal pentapeptides of the beta-chains of human adult hemoglobin, HbA, and its glycated form HbA1c. To differentiate between peptides differing solely in a glucose adduct MIP nanofilms were prepared by a two-step hierarchical electrosynthesis that involves first the chemisorption of a cysteinyl derivative of the pentapeptide followed by electropolymerization of scopoletin. This approach was compared with a random single-step electrosynthesis using scopo-letin/pentapeptide mixtures. Electrochemical monitoring of the peptide binding to the MIP nanofilms by means of redox probe gating revealed a superior affinity of the hierarchical approach with a Kd value of 64.6 nM towards the related target. Changes in the electrosynthesized non-imprinted polymer and MIP nanofilms during chemical, electrochemical template removal and rebinding were substantiated in situ by monitoring the characteristic bands of both target peptides and polymer with surface enhanced infrared absorption spectroscopy. This rational approach led to MIPs with excellent selectivity and provided key mechanistic insights with respect to electrosynthesis, rebinding and stability of the formed MIPs. KW - SEIRA spectroelectrochemistry KW - peptide imprinting KW - electrosynthesis KW - MIP KW - glycated peptide Y1 - 2021 U6 - https://doi.org/10.1016/j.electacta.2021.138236 SN - 0013-4686 SN - 1873-3859 VL - 381 PB - Elsevier CY - New York, NY [u.a.] ER - TY - JOUR A1 - Wollenberger, Ursula A1 - Schubert, Florian A1 - Pfeiffer, Dorothea A1 - Scheller, Frieder W. T1 - Recycling sensors based on kinases : proceedings of Mosbach Symposion on Biochemical Technology Y1 - 1996 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Wollenberger, Ursula A1 - Pfeiffer, Dorothea A1 - Schubert, Florian T1 - Overview of biosensor technology : proceedings of Mosbach Symposion on Biochemical Technology Y1 - 1996 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Schubert, Florian A1 - Bier, Frank Fabian T1 - Vom Biosensor zur Nanobiotechnologie Y1 - 1995 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Wollenberger, Ursula A1 - Schubert, Florian A1 - Pfeiffer, Dorothea A1 - Markower, Alexander A1 - McNeil, C. J. T1 - Multienzyme biosensors : coupled enzyme reactions and enzyme activation Y1 - 1993 ER - TY - JOUR A1 - Pfeiffer, Dorothea A1 - Scheller, Frieder W. A1 - Schubert, Florian A1 - Setz, K. T1 - Amperometric enzyme electrodes for lactate and glucose determinations in highly diluted and undiluted media Y1 - 1993 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Kirstein, Dieter A1 - Schubert, Florian A1 - Pfeiffer, Dorothea A1 - McNeil, C. J. T1 - Enzymes in electrochemical biosensors Y1 - 1993 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Pfeiffer, Dorothea A1 - Schubert, Florian A1 - Wollenberger, Ursula T1 - Enzyme - based electrodes Y1 - 1995 ER - TY - JOUR A1 - Wollenberger, Ursula A1 - Schubert, Florian A1 - Pfeiffer, Dorothea A1 - Scheller, Frieder W. T1 - Enhancing biosensor performance using multienzyme systems Y1 - 1993 ER - TY - JOUR A1 - Peng, Lei A1 - Yarman, Aysu A1 - Jetzschmann, Katharina J. A1 - Jeoung, Jae-Hun A1 - Schad, Daniel A1 - Dobbek, Holger A1 - Wollenberger, Ursula A1 - Scheller, Frieder W. T1 - Molecularly Imprinted Electropolymer for a Hexameric Heme Protein with Direct Electron Transfer and Peroxide Electrocatalysis JF - SENSORS N2 - For the first time a molecularly imprinted polymer (MIP) with direct electron transfer (DET) and bioelectrocatalytic activity of the target protein is presented. Thin films of MIPs for the recognition of a hexameric tyrosine-coordinated heme protein (HTHP) have been prepared by electropolymerization of scopoletin after oriented assembly of HTHP on a self-assembled monolayer (SAM) of mercaptoundecanoic acid (MUA) on gold electrodes. Cavities which should resemble the shape and size of HTHP were formed by template removal. Rebinding of the target protein sums up the recognition by non-covalent interactions between the protein and the MIP with the electrostatic attraction of the protein by the SAM. HTHP bound to the MIP exhibits quasi-reversible DET which is reflected by a pair of well pronounced redox peaks in the cyclic voltammograms (CVs) with a formal potential of -184.4 +/- 13.7 mV vs. Ag/AgCl (1 M KCl) at pH 8.0 and it was able to catalyze the cathodic reduction of peroxide. At saturation the MIP films show a 12-fold higher electroactive surface concentration of HTHP than the non-imprinted polymer (NIP). KW - hydrogen peroxide KW - bioelectrocatalysis KW - molecularly imprinted polymers KW - direct electron transfer KW - self-assembled monolayer Y1 - 2016 U6 - https://doi.org/10.3390/s16030272 SN - 1424-8220 VL - 16 SP - 1343 EP - 1364 PB - MDPI CY - Basel ER - TY - JOUR A1 - Tadjoung Waffo, Armel Franklin A1 - Yesildag, Cigdem A1 - Caserta, Giorgio A1 - Katz, Sagie A1 - Zebger, Ingo A1 - Lensen, Marga C. A1 - Wollenberger, Ulla A1 - Scheller, Frieder W. A1 - Altintas, Zeynep T1 - Fully electrochemical MIP sensor for artemisinin JF - Sensors and actuators : B, Chemical N2 - This study aims to develop a rapid, sensitive and cost-effective biomimetic electrochemical sensor for artemisinin determination in plant extracts and for pharmacokinetic studies. A novel molecularly imprinted polymer (MIP)based electrochemical sensor was developed by electropolymerization of o-phenylenediamine (o-PD) in the presence of artemisinin on gold wire surface for sensitive detection of artemisinin. The experimental parameters, including selection of functional monomer, polymerization conditions, template extraction after polymerization, influence of pH and buffer were all optimized. Every step of imprinted film synthesis were evaluated by employing voltammetry techniques, surface-enhanced infrared absorption spectroscopy (SEIRAS) and atomic force microscopy (AFM). The specificity was further evaluated by investigating non-specific artemisinin binding on non-imprinted polymer (NIP) surfaces and an imprinting factor of 6.8 was achieved. The artemisinin imprinted polymers using o-PD as functional monomer have provided highly stable and effective binding cavities for artemisinin. Cross-reactivity studies with drug molecules showed that the MIPs are highly specific for artemisinin. The influence of matrix effect was further investigated both in artificial plant matrix and diluted human serum. The results revealed a high affinity of artemisinin-MIP with dissociation constant of 7.3 x 10(-9) M and with a detection limit of 0.01 mu M and 0.02 mu M in buffer and plant matrix, respectively. KW - Electro-synthesized molecularly imprinted polymer KW - o-Phenylenediamine KW - Artemisinin KW - Antimalarial drug detection KW - Electrochemical sensor Y1 - 2018 U6 - https://doi.org/10.1016/j.snb.2018.08.018 SN - 0925-4005 VL - 275 SP - 163 EP - 173 PB - Elsevier CY - Lausanne ER - TY - JOUR A1 - Zhang, Xiaorong A1 - Caserta, Giorgio A1 - Yarman, Aysu A1 - Supala, Eszter A1 - Tadjoung Waffo, Armel Franklin A1 - Wollenberger, Ulla A1 - Gyurcsanyi, Robert E. A1 - Zebger, Ingo A1 - Scheller, Frieder W. T1 - "Out of Pocket" protein binding BT - a dilemma of epitope imprinted polymers revealed for human hemoglobin JF - Chemosensors N2 - The epitope imprinting approach applies exposed peptides as templates to synthesize Molecularly Imprinted Polymers (MIPs) for the recognition of the parent protein. While generally the template protein binding to such MIPs is considered to occur via the epitope-shaped cavities, unspecific interactions of the analyte with non-imprinted polymer as well as the detection method used may add to the complexity and interpretation of the target rebinding. To get new insights on the effects governing the rebinding of analytes, we electrosynthesized two epitope-imprinted polymers using the N-terminal pentapeptide VHLTP-amide of human hemoglobin (HbA) as the template. MIPs were prepared either by single-step electrosynthesis of scopoletin/pentapeptide mixtures or electropolymerization was performed after chemisorption of the cysteine extended VHLTP peptide. Rebinding of the target peptide and the parent HbA protein to the MIP nanofilms was quantified by square wave voltammetry using a redox probe gating, surface enhanced infrared absorption spectroscopy, and atomic force microscopy. While binding of the pentapeptide shows large influence of the amino acid sequence, all three methods revealed strong non-specific binding of HbA to both polyscopoletin-based MIPs with even higher affinities than the target peptides. KW - Molecularly Imprinted Polymers KW - epitope imprinting KW - non-specific KW - binding KW - redox gating KW - SEIRA spectroelectrochemistry Y1 - 2021 U6 - https://doi.org/10.3390/chemosensors9060128 SN - 2227-9040 VL - 9 IS - 6 PB - MDPI CY - Basel ER - TY - JOUR A1 - Menger, Marcus A1 - Yarman, Aysu A1 - Erdössy, Júlia A1 - Yildiz, Huseyin Bekir A1 - Gyurcsányi, Róbert E. A1 - Scheller, Frieder W. T1 - MIPs and Aptamers for Recognition of Proteins in Biomimetic Sensing JF - Biosensors : open access journal N2 - Biomimetic binders and catalysts have been generated in order to substitute the biological pendants in separation techniques and bioanalysis. The two major approaches use either "evolution in the test tube" of nucleotides for the preparation of aptamers or total chemical synthesis for molecularly imprinted polymers (MIPs). The reproducible production of aptamers is a clear advantage, whilst the preparation of MIPs typically leads to a population of polymers with different binding sites. The realization of binding sites in the total bulk of the MIPs results in a higher binding capacity, however, on the expense of the accessibility and exchange rate. Furthermore, the readout of the bound analyte is easier for aptamers since the integration of signal generating labels is well established. On the other hand, the overall negative charge of the nucleotides makes aptamers prone to non-specific adsorption of positively charged constituents of the sample and the "biological" degradation of non-modified aptamers and ionic strength-dependent changes of conformation may be challenging in some application. KW - biomimetic recognition elements KW - aptamers KW - molecularly imprinted polymers KW - chemical sensors KW - aptasensors KW - in vitro selection KW - SELEX Y1 - 2016 U6 - https://doi.org/10.3390/bios6030035 SN - 2079-6374 VL - 6 SP - 4399 EP - 4413 PB - MDPI CY - Basel ER -