title: Potential-dependent surface-enhanced resonance Raman spectroscopy at nanostructured TiO2 : a case study on cytochrome b5.
abstract: Nanostructured titanium dioxide (TiO2 ) electrodes, prepared by anodization of titanium, are employed to probe the electron-transfer process of cytochrome b5 (cyt b5 ) by surface-enhanced resonance Raman (SERR) spectroscopy. Concomitant with the increased nanoscopic surface roughness of TiO2 , achieved by raising the anodization voltage from 10 to 20 V, the enhancement factor increases from 2.4 to 8.6, which is rationalized by calculations of the electric field enhancement. Cyt b5 is immobilized on TiO2 under preservation of its native structure but it displays a non-ideal redox behavior due to the limited conductivity of the electrode material. The electron-transfer efficiency which depends on the crystalline phase of TiO2 has to be improved by appropriate doping for applications in bioelectrochemistry.
authors.affiliation: Technische Universität Berlin, Institut für Chemie, Sekr. PC14, Strasse des 17. Juni 135, D-10623 Berlin, Germany.
authors.forename: Xiao Xia
authors.initials: XX
authors.lastname: Han
authors.forename: Christopher
authors.initials: C
authors.lastname: Köhler
authors.forename: Jacek
authors.initials: J
authors.lastname: Kozuch
authors.forename: Uwe
authors.initials: U
authors.lastname: Kuhlmann
authors.forename: Lars
authors.initials: L
authors.lastname: Paasche
authors.forename: Arumugam
authors.initials: A
authors.lastname: Sivanesan
authors.forename: Inez M
authors.initials: IM
authors.lastname: Weidinger
authors.forename: Peter
authors.initials: P
authors.lastname: Hildebrandt
mesh_terms: D000327:Adsorption; D001672:Biocompatible Materials / Q000737:chemistry*; D002384:Catalysis; D003460:Crystallization; D015786:Cytochromes b5 / Q000737:chemistry*; D004566:Electrodes; D004583:Electrons; D006418:Heme / Q000737:chemistry; D006801:Humans; D049329:Nanostructures; D036103:Nanotechnology; D010084:Oxidation-Reduction; D013053:Spectrophotometry; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; C009495:titanium dioxide; D006418:Heme; D015786:Cytochromes b5; D014025:Titanium
keywords: anisotropy; electron transfer; field enhancements; redox proteins; surface-enhanced Raman spectroscopy; titanium dioxide