Electrochemically gated oligopeptide nanowires bridging gold electrodes: novel bio-nanoelectronic switches operating in aqueous electrolytic environments.

We present electronic structure and transport calculations that reveal that oligopeptide based molecular nanowires support unoccupied extended electronic states that span the length of the nanowire and are resistant to disorder. Electrochemical gating in aqueous electrolytes is shown to bring these extended states into resonance with the Fermi level of gold electrodes, transforming these nanowires from insulators into conductors. Thus oligopeptide nanowires are promising candidates for bionanoelectronic switches operating in the aqueous electrolytic environments native to biological systems.