EMANUELA GATTO¹, FERNANDO FORMAGGIO², CLAUDIO TONIOLO², MARIANO VENANZI1*
*Corresponding author
1. University of Rome “Tor Vergata”, Department of Chemical Sciences and Technologies, Via della Ricerca Scientifica 1, 00133 Rome, Italy
2. University of Padova, ICB, CNR, Padova Unit, Department of Chemistry, Via Marzolo 1, 35131 Padova, Italy

Abstract

In this contribution we report on our recent studies on peptide-based self-assembled monolayers (SAMs). We show that helical oligopeptides formed by Cα-tetrasubstituted Cα-amino acids can form stable and densely-packed nanometric films on a gold surface. Three issues will be discussed: I) the morphology of peptide thiol SAMs on a gold surface, II) the electron transfer properties of peptide SAMs functionalized with electro- or photoactive probes, and III) the versatility of helical peptide building blocks in the engineering of complex nanostructures. These findings will pave the way for feasible applications in the fields of electrochemical sensing, molecular electronics, and bionanotechnology.

The spontaneous organization of molecular building blocks (bottom-up self-assembly) is the most appropriate approach for the construction of controlled supramolecular structures at nanometric level (1). This strategy allows for the molecular design of new-concept, smart materials with feasible applications in tissue engineering, controlled drug release, nucleic acid and protein sensing, organic photovoltaics and molecular electronics (2–4). Among the supramolecular architectures obtained by self-assembly, Self-Assembled Monolayers (SAM) have been demonstrated to be the most suitable tool for modifying the surface properties of inorganic compounds (metals, semiconductors, polymers), paving the way to the realization of hybrid devices (soft meets hard) (5). 

Although most of the research activity on organic SAMs has been so far devoted to alkanethiol compounds, peptide thiol building blocks show unique properties that make them ideal candidates for new bioinspired technological applications. Peptides can be easily functionalized, can be designed to adopt specific secondary structures and feature controlled self-assembly properties, expanding the catalogue of stabilizing ...