The Hydrogen-Bonded Ferrocenylmethanol: Mediation of Electron Transfer for Physically Adsorbed Glucose Oxidase

Abstract

The mechanism of electron transfer of ferrocenylmethanol through the self-assembled monolayer (SAM) of mercaptosuccinic acid (MSA) on gold was investigated. A key finding is that the hydrogen-bonded FcMeOH plays the role of a mediator in the electron transfer involving the physically adsorbed glucose oxidase at the MSA SAM surface. The space-conformation of the hydrogen-bonding between FcMeOH and MSA was obtained by computational methods. The FcMeOH interacts with MSA via the strong hydrogen bond with the short distance around 1.9 Å at two different binding sites, approving the statements of hydrogen-bonding. The intermolecular hydrogen-bonding between redox mediator (FcMeOH) and the artificial self-assembled monolayer (MSA) is evident, and the mechanistic study of heterogeneous electron transfer kinetics is meaningful for the biosensor applications.