Electron Transfer Mechanism in Helical Peptides

Electrochemical studies of a set of ferrocene-labeled helical peptides of increasing length were carried out by forming self-assembled monolayers (SAMs) on gold electrodes. Electron transfer (ET) rates showed a very weakly distance dependent nature that has been interpreted as a result of a dynamically controlled tunneling mechanism. Specifically, the slow equilibrium between the α- and the 3₁₀ helical conformers in a SAM has been invoked, and the rate of formation of the more conductive 3₁₀ conformer has been proposed to be related to the ET rates observed