Self-assembled monolayers formed by helical peptide building blocks: a new tool for bioinspired nanotechnology

In this contribution, we report on our studies on peptide-based self-assembled monolayers (SAMs). In particular, we show that helical oligopeptides formed by Cα-tetrasubstituted amino acids and functionalized at the N terminus by a lipoic acid can form stable and densely packed nanometric films on a gold surface. The morphology of the peptide SAM was characterized by ultra-high-vacuum scanning tunneling microscopy and spectroscopic techniques, whereas their electronic conductivity was investigated by cyclic voltammetry and chronoamperometry in peptides functionalized with electroactive probes and by photocurrent generation experiments on peptides functionalized with photoactive groups. The versatility of helical peptide building blocks in the engineering of complex nanostructures is highlighted by the formation of multicomponent SAMs with a ‘soft’ approach based on the setting up of weak intermolecular interactions.