@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{SivanesanKalaivaniFischeretal.2012, author = {Sivanesan, Arumugam and Kalaivani, Govindasamy and Fischer, Anna and Stiba, Konstanze and Leimk{\"u}hler, Silke and Weidinger, Inez M.}, title = {Complementary surface-enhanced resonance raman Spectroscopic Biodetection of mixed protein solutions by Chitosan- and Silica-Coated Plasmon-Tuned Silver Nanoparticles}, series = {Analytical chemistry}, volume = {84}, journal = {Analytical chemistry}, number = {13}, publisher = {American Chemical Society}, address = {Washington}, issn = {0003-2700}, doi = {10.1021/ac301001a}, pages = {5759 -- 5764}, year = {2012}, abstract = {Silver nanoparticles with identical plasmonic properties but different surface functionalities are synthesized and tested as chemically selective surface-enhanced resonance Raman (SERR) amplifiers in a two-component protein solution. The surface plasmon resonances of the particles are tuned to 413 nm to match the molecular resonance of protein heme cofactors. Biocompatible functionalization of the nanoparticles with a thin film of chitosan yields selective SERR enhancement of the anionic protein cytochrome b(5), whereas functionalization with SiO2 amplifies only the spectra of the cationic protein cytochrome c. As a result, subsequent addition of the two differently functionalized particles yields complementary information on the same mixed protein sample solution. Finally, the applicability of chitosan-coated Ag nanoparticles for protein separation was tested by in situ resonance Raman spectroscopy.}, language = {en} }