Electroconductive and photocurrent generation properties of self-assembled monolayers formed by functionalized, conformationally-constrained peptides on gold electrodes.

The electroconductive properties and photocurrent generation capabilities of self-assembled monolayers formed by conformationally-constrained hexapeptides were studied by cyclic voltammetry, chronoamperometry, and photocurrent generation experiments. Lipoic acid was covalently linked to the N-terminus of the peptides investigated to exploit the high affinity of the disulfide group to the gold substrates. Smart functionalization of the peptide scaffold with a redox-active (TOAC) or a photosensitizer (Trp) amino acid allowed us to study the efficiency of peptide-based self-assembled monolayers to mediate electron transfer and photoinduced electron transfer processes on gold substrates. Interdigitated microelectrodes have shown higher film stability under photoexcitation, lower dark currents, and higher sensitivity with respect to standard gold electrodes.