Voltammetric and electrochemical impedance study of ferrocenyl containing beta-peptide monolayers on gold

Abstract

An investigation of the kinetics of electron transfer though a self-assembled monolayer containing long chain alkanethiol and β-peptide components and a terminating ferrocene group has been carried out at a polycrystalline gold electrode. Cyclic voltammetry and electrochemical impedance spectroscopy in aqueous and mixed aqueous-methanol solutions showed the rate of electron transfer varied from approximately 5 in water to 29 s-1 in methanol. This difference is attributed to a change in the alkanethiol tilt angle in the film in response to hydrogen bonding disruption of the peptide to allow greater molecular motion during electron transfer. © 2011 American Chemical Society.