@article{NeumannKielbRustametal.2017, author = {Neumann, Bettina and Kielb, Patrycja and Rustam, Lina and Fischer, Anna and Weidinger, Inez M. and Wollenberger, Ulla}, title = {Bioelectrocatalytic Reduction of Hydrogen Peroxide by Microperoxidase-11 Immobilized on Mesoporous Antimony-Doped Tin Oxide}, series = {ChemElectrChem}, volume = {4}, journal = {ChemElectrChem}, number = {4}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {2196-0216}, doi = {10.1002/celc.201600776}, pages = {913 -- 919}, year = {2017}, abstract = {The heme-undecapeptide microperoxidase-11 (MP-11) was immobilized on mesoporous antimony-doped tin oxide (ATO) thin-film electrodes modified with the positively charged binding promotor polydiallyldimethylammonium chloride. Surface concentrations of MP-11 of 1.5 nmol cm(-2) were sufficiently high to enable spectroelectrochemical analyses. UV/Vis spectroscopy and resonance Raman spectroscopy revealed that immobilized MP-11 adopts a six-coordinated low-spin conformation, as in solution in the presence of a polycation. Cathodic reduction of hydrogen peroxide at potentials close to +500mV versus Ag/AgCl indicates that the reaction proceeds via a Compound I-type like intermediate, analogous to natural peroxidases, and confirms mesoporous ATO as a suitable host material for adsorbing the heme-peptide in its native state. A hydrogen peroxide sensor is proposed by using the bioelectrocatalytic properties of the MP-11-modified ATO.}, language = {en} } @article{KielbSezerKatzetal.2015, author = {Kielb, Patrycja and Sezer, Murat and Katz, Sagie and Lopez, Francesca and Schulz, Christopher and Gorton, Lo and Ludwig, Roland and Wollenberger, Ursula and Zebger, Ingo and Weidinger, Inez M.}, title = {Spectroscopic Observation of Calcium-Induced Reorientation of Cellobiose Dehydrogenase Immobilized on Electrodes and its Effect on Electrocatalytic Activity}, series = {ChemPhysChem : a European journal of chemical physics and physical chemistry}, volume = {16}, journal = {ChemPhysChem : a European journal of chemical physics and physical chemistry}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1439-4235}, doi = {10.1002/cphc.201500112}, pages = {1960 -- 1968}, year = {2015}, abstract = {Cellobiose dehydrogenase catalyzes the oxidation of various carbohydrates and is considered as a possible anode catalyst in biofuel cells. It has been shown that the catalytic performance of this enzyme immobilized on electrodes can be increased by presence of calcium ions. To get insight into the Ca2+-induced changes in the immobilized enzyme we employ surface-enhanced vibrational (SERR and SEIRA) spectroscopy together with electrochemistry. Upon addition of Ca2+ ions electrochemical measurements show a shift of the catalytic turnover signal to more negative potentials while SERR measurements reveal an offset between the potential of heme reduction and catalytic current. Comparing SERR and SEIRA data we propose that binding of Ca2+ to the heme induces protein reorientation in a way that the electron transfer pathway of the catalytic FAD center to the electrode can bypass the heme cofactor, resulting in catalytic activity at more negative potentials.}, language = {en} } @article{AlbrechtVandewalTumblestonetal.2014, author = {Albrecht, Steve and Vandewal, Koen and Tumbleston, John R. and Fischer, Florian S. U. and Douglas, Jessica D. and Frechet, Jean M. J. and Ludwigs, Sabine and Ade, Harald W. and Salleo, Alberto and Neher, Dieter}, title = {On the efficiency of charge transfer state splitting in polymer: Fullerene solar cells}, series = {Advanced materials}, volume = {26}, journal = {Advanced materials}, number = {16}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0935-9648}, doi = {10.1002/adma.201305283}, pages = {2533 -- 2539}, year = {2014}, language = {en} }