Study on the electron transfer of ferrocene-modified self-assembled monolayers and its application for biosensor platform

Abstract

Electrochemical detection method was widely used as a biosensor. It was allowed to make a fast, direct, cheap and able-to-be automated biosensor. Existing electrochemical sensors required complicated steps to attach an enzyme and a redox-active molecule to solve the overpotential problem in electrical signal due to additional layers of SAMs and biomolecules. In this study, we made a simple platform using a ferrocenyl undecanethiol $(Fc(CH_2)_{11}SH)$ as an electron transfer mediator and mercapto dodecanoic acid (MDA) for immobilization of biomolecules. We had developed the platform as an enzyme-linked electrochemical sensor to detect biomolecular recognitions. Avidin and biotin have the strongest non-covalent bonding, so the interaction was widely used to attach the biomolecule in biosensor. In this paper biospecific interaction of avidin to biotinylated monolayers was successfully detected by the subsequent association with biotinylated alkaline phosphatase. It is first paper about biosensor using $Fc(CH_2)_{11}SH$ as an electron transfer mediator.