An investigation of the conductivity of peptide nanotube networks prepared by enzyme-triggered self-assemblyElectronic supplementary information (ESI) available: Fig. S1 to S4. See DOI: 10.1039/b9nr00233b

We demonstrate that nanotubular networks formed by enzyme-triggered self-assembly of Fmoc-L 3 (9-fluorenylmethoxycarbonyl-tri-leucine) show significant charge transport. FT-IR, fluorescence spectroscopy and wide angle X-ray scattering (WAXS) data confirm formation of β-sheets that are locked together via π-stacking interactions. Molecular dynamics simulations confirmed the π-π stacking distance between fluorenyl groups to be 3.6-3.8 Å. Impedance spectroscopy demonstrated that the nanotubular xerogel networks possess minimum sheet resistances of 0.1 MΩ/sq in air and 500 MΩ/sq in vacuum (pressure: 1.03 mbar) at room temperature, with the conductivity scaling linearly with the mass of peptide in the network. These materials may provide a platform to interface biological components with electronics. We demonstrate that nanotubular networks formed by enzyme-triggered self-assembly of Fmoc-L 3 (9-fluorenylmethoxycarbonyl-tri-leucine) show significant charge transport under vacuum conditions.