Redox and Electrocatalytic Properties of Mimochrome VI, a Synthetic Heme-Peptide Adsorbed on Gold

MimochromeVI (MC-VI) is a synthetic heme-peptide containing a helix-heme-helix sandwich motif designed to reproduce the catalytic activity of heme oxidases. The thermodynamics of Fe(III) to Fe(II) reduction and the kinetics of the electron transfer process for MC-VI immobilized through hydrophobic interactions on a gold electrode coated with a nonpolar SAM of decane-1-thiol have been determined through cyclic voltammetry. Immobilization slightly affects the reduction potential of MC-VI, which in these conditions electrocatalytically turns over molecular oxygen. This work sets the premises for the exploitation of totally-synthetic mimochrome-modified electrode surfaces for clinical and pharmaceutical biosensing.