title: Detection of molecular interactions with modified ferrocene self-assembled monolayers.
abstract: Ferrocene-terminated self-assembled monolayers (Fc-SAMs) are one of the most studied molecular aggregates on metal electrodes. They are easy to fabricate and provide a stable and reproducible system to investigate the effect of the microenvironment on the electron transfer parameters. We propose a novel application for Fc-SAMs, the detection of molecular interactions, based on the modification of the SAM with target-specific receptors. Mixed SAMs were fabricated by coimmobilization on Au electrodes of thiolated alkane chains with three different head groups: hydroxy terminating head group, ferrocene head group, and a functional head group such as biotin. Upon binding, the intrinsic electric charge of the target (e.g., streptavidin) modifies the electrostatic potential at the plane of electron transfer, causing a shift in the formal potential E degrees '. The SAMs were characterized by AC voltammetry. The detection mechanism is confirmed by measurements of formal potential as a function of electrolyte pH.
authors.affiliation: University of Cambridge, Engineering Department, Electrical Engineering Division, UK.
authors.forename: Man Yi
authors.initials: MY
authors.lastname: Ho
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.forename: Pedro
authors.initials: P
authors.lastname: Estrela
authors.forename: Sarah
authors.initials: S
authors.lastname: Goodchild
authors.forename: Piero
authors.initials: P
authors.lastname: Migliorato