Cytochrome C as a benchmark system for a two-layer gold surface with improved surface-enhancement for spectro-electrochemistry

Issue title: From Molecule to Tissue: XIII European Conference on the Spectroscopy of Biological Molecules, Palermo, Italy, August 28–September 2, 2009, Part 1 of 2

Article type: Research Article

Authors: Nowak, Christoph^; | Schach, Denise^; | Grosserüschkamp, Marc^; | Knoll, Wolfgang | Naumann, Renate L.C.^{; ;}

Affiliations: Max Planck Institute for Polymer Research, Mainz, Germany | Austrian Institute of Technology GmbH–ARC, Vienna, Austria

Note: [] Corresponding author: Renate L.C. Naumann, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany. Tel.: +49 6131 379 157; Fax: +49 6131 379 100; E-mail: [email protected].

Abstract: A two-layer gold surface is developed for use with electrochemistry followed by surface-enhanced infrared absorption spectroscopy (SEIRAS) consisting of a conducting underlayer onto which Au nanoparticles (AuNPs) are grown by self-catalyzed electroless deposition. AuNPs are grown on protruding substructures of the 25 nm thin underlayer. The enhancement factor of the two-layer gold surface is controlled by the growth conditions. Cytochrome c adsorbed to a self-assembled monolayer of mercaptoethanol is used as a benchmark system for the investigation of complex heme proteins from the respiratory chain such as cytochrome c oxidase and the bc1 complex. Under optimum conditions the absorbance of the amide I band of cytochrome c is increased by a factor of 5 vs. classical SEIRAS surface. Reversible reduction/oxidation of cytochrome c on the two-layer gold surface is shown to take place by cyclic voltammetry.

Keywords: Surface-enhancement, SEIRAS, cytochrome C, spectro-electrochemistry, two-layer gold surface

DOI: 10.3233/SPE-2010-0425

Journal: Spectroscopy, vol. 24, no. 1-2, pp. 173-176, 2010