TY - JOUR A1 - Welzel, H.-P. A1 - Kossmehl, G. A1 - Engelmann, G. A1 - Neumann, B. A1 - Wollenberger, Ursula A1 - Scheller, Frieder W. A1 - Schröder, W. T1 - Reactive groups on polymer covered electrodes, 4. Lactate-oxidase-biosensor based on electrodes modifies by polyphiophene Y1 - 1996 ER - TY - JOUR A1 - Neumann, Bettina A1 - Götz, Robert A1 - Wrzolek, Pierre A1 - Scheller, Frieder W. A1 - Weidinger, Inez M. A1 - Schwalbe, Matthias A1 - Wollenberger, Ulla T1 - Enhancement of the Electrocatalytic Activity of Thienyl-Substituted Iron Porphyrin Electropolymers by a Hangman Effect JF - ChemCatChem : heterogeneous & homogeneous & bio- & nano-catalysis ; a journal of ChemPubSoc Europe N2 - The thiophene-modified iron porphyrin FeT3ThP and the respective iron Hangman porphyrin FeH3ThP, incorporating a carboxylic acid hanging group in the second coordination sphere of the iron center, were electropolymerized on glassy carbon electrodes using 3,4-ethylenedioxythiophene (EDOT) as co-monomer. Scanning electron microscopy images and Resonance Raman spectra demonstrated incorporation of the porphyrin monomers into a fibrous polymer network. Porphyrin/polyEDOT films catalyzed the reduction of molecular oxygen in a four-electron reaction to water with onset potentials as high as +0.14V vs. Ag/AgCl in an aqueous solution of pH7. Further, FeT3ThP/polyEDOT films showed electrocatalytic activity towards reduction of hydrogen peroxide at highly positive potentials, which was significantly enhanced by introduction of the carboxylic acid hanging group in FeH3ThP. The second coordination sphere residue promotes formation of a highly oxidizing reaction intermediate, presumably via advantageous proton supply, as observed for peroxidases and catalases making FeH3ThP/polyEDOT films efficient mimics of heme enzymes. KW - activation of oxygen species KW - electro-polymerization KW - Hangman porphyrin KW - heterogeneous catalysis KW - immobilization Y1 - 2018 U6 - https://doi.org/10.1002/cctc.201800934 SN - 1867-3880 SN - 1867-3899 VL - 10 IS - 19 SP - 4353 EP - 4361 PB - Wiley-VCH CY - Weinheim ER - TY - GEN A1 - Yarman, Aysu A1 - Jetzschmann, Katharina J. A1 - Neumann, Bettina A1 - Zhang, Xiaorong A1 - Wollenberger, Ulla A1 - Cordin, Aude A1 - Haupt, Karsten A1 - Scheller, Frieder W. T1 - Enzymes as tools in MIP-sensors T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Molecularly imprinted polymers (MIPs) have the potential to complement antibodies in bioanalysis, are more stable under harsh conditions, and are potentially cheaper to produce. However, the affinity and especially the selectivity of MIPs are in general lower than those of their biological pendants. Enzymes are useful tools for the preparation of MIPs for both low and high-molecular weight targets: As a green alternative to the well-established methods of chemical polymerization, enzyme-initiated polymerization has been introduced and the removal of protein templates by proteases has been successfully applied. Furthermore, MIPs have been coupled with enzymes in order to enhance the analytical performance of biomimetic sensors: Enzymes have been used in MIP-sensors as tracers for the generation and amplification of the measuring signal. In addition, enzymatic pretreatment of an analyte can extend the analyte spectrum and eliminate interferences. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1098 KW - enzymatic MIP synthesis KW - template digestion KW - enzyme tracer KW - enzymatic analyte conversion KW - molecularly imprinted polymers Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-474642 SN - 1866-8372 IS - 1098 ER - TY - JOUR A1 - Yarman, Aysu A1 - Jetzschmann, Katharina J. A1 - Neumann, Bettina A1 - Zhang, Xiaorong A1 - Wollenberger, Ulla A1 - Cordin, Aude A1 - Haupt, Karsten A1 - Scheller, Frieder W. T1 - Enzymes as Tools in MIP-Sensors JF - Chemosensors N2 - Molecularly imprinted polymers (MIPs) have the potential to complement antibodies in bioanalysis, are more stable under harsh conditions, and are potentially cheaper to produce. However, the affinity and especially the selectivity of MIPs are in general lower than those of their biological pendants. Enzymes are useful tools for the preparation of MIPs for both low and high-molecular weight targets: As a green alternative to the well-established methods of chemical polymerization, enzyme-initiated polymerization has been introduced and the removal of protein templates by proteases has been successfully applied. Furthermore, MIPs have been coupled with enzymes in order to enhance the analytical performance of biomimetic sensors: Enzymes have been used in MIP-sensors as tracers for the generation and amplification of the measuring signal. In addition, enzymatic pretreatment of an analyte can extend the analyte spectrum and eliminate interferences. KW - enzymatic MIP synthesis KW - template digestion KW - enzyme tracer KW - enzymatic analyte conversion KW - molecularly imprinted polymers Y1 - 2017 U6 - https://doi.org/10.3390/chemosensors5020011 SN - 2227-9040 VL - 5 PB - MDPI CY - Basel ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Bier, Frank Fabian A1 - Neumann, B. T1 - Bioindikation in aquatischen Ökosystemen : Bioindikation in limnischen und küstennahen Ökosystemen ; Grundlagen, Verfahren und Methoden Y1 - 1994 PB - Fischer CY - Jena ER - TY - JOUR A1 - Grott, Matthias A1 - Knollenberg, J. A1 - Hamm, M. A1 - Ogawa, K. A1 - Jaumann, R. A1 - Otto, Katharina Alexandra A1 - Delbo, M. A1 - Michel, P. A1 - Biele, J. A1 - Neumann, W. A1 - Knapmeyer, M. A1 - Kuehrt, E. A1 - Senshu, H. A1 - Okada, T. A1 - Helbert, J. A1 - Maturilli, A. A1 - Müller, N. A1 - Hagermann, A. A1 - Sakatani, N. A1 - Tanaka, S. A1 - Arai, T. A1 - Mottola, S. A1 - Tachibana, S. A1 - Pelivan, Ivanka A1 - Drube, L. A1 - Vincent, J-B A1 - Yano, H. A1 - Pilorget, C. A1 - Matz, K. D. A1 - Schmitz, N. A1 - Koncz, A. A1 - Schröder, S. E. A1 - Trauthan, F. A1 - Schlotterer, M. A1 - Krause, C. A1 - Ho, T-M A1 - Moussi-Soffys, A. T1 - Low thermal conductivity boulder with high porosity identified on C-type asteroid (162173) Ryugu JF - Nature astronomy N2 - C-type asteroids are among the most pristine objects in the Solar System, but little is known about their interior structure and surface properties. Telescopic thermal infrared observations have so far been interpreted in terms of a regolith-covered surface with low thermal conductivity and particle sizes in the centimetre range. This includes observations of C-type asteroid (162173) Ryugu1,2,3. However, on arrival of the Hayabusa2 spacecraft at Ryugu, a regolith cover of sand- to pebble-sized particles was found to be absent4,5 (R.J. et al., manuscript in preparation). Rather, the surface is largely covered by cobbles and boulders, seemingly incompatible with the remote-sensing infrared observations. Here we report on in situ thermal infrared observations of a boulder on the C-type asteroid Ryugu. We found that the boulder’s thermal inertia was much lower than anticipated based on laboratory measurements of meteorites, and that a surface covered by such low-conductivity boulders would be consistent with remote-sensing observations. Our results furthermore indicate high boulder porosities as well as a low tensile strength in the few hundred kilopascal range. The predicted low tensile strength confirms the suspected observational bias6 in our meteorite collections, as such asteroidal material would be too frail to survive atmospheric entry7. Y1 - 2020 U6 - https://doi.org/10.1038/s41550-019-0832-x SN - 2397-3366 VL - 3 IS - 11 SP - 971 EP - 976 PB - Nature Publishing Group CY - London ER - TY - JOUR A1 - Welzel, H.-P. A1 - Kossmehl, G. A1 - Engelmann, G. A1 - Neumann, B. A1 - Wollenberger, Ursula A1 - Scheller, Frieder W. T1 - Electrochemical polymerization of functionalized thiohene derivatives for immobilization of proteins Y1 - 1997 ER - TY - JOUR A1 - Li, Junbai A1 - Miller, Reinhard A1 - Wüstneck, Rainer A1 - Möhwald, Helmuth A1 - Neumann, A. W. T1 - News of pendant drop technique as a film balance at liquid/liquid interfaces Y1 - 1995 ER - TY - JOUR A1 - Riedel, K. A1 - Beyersdorf-Radeck, Baerbel A1 - Neumann, B. A1 - Scheller, Frieder W. A1 - Schmid, Rolf D. T1 - Microbial sensors for determination of aromatics and their chloro derivatives. Part III: Determination of chlorinated phenols using a biosensor containing Trichosporon beigelii (cutaneum) Y1 - 1995 ER - TY - JOUR A1 - Wollenberger, Ursula A1 - Neumann, B. A1 - Scheller, Frieder W. T1 - Development of a biomimetic alkane sensor f Y1 - 1998 ER -