Abstract: Conductive films formed from composites of phenylalanine and poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS). The composite films formed by introducing aromatic amino acid phenylalanine in PEDOT:PSS improved the conductivity of the film to about 594 S/cm, a 400% increment compared to the conductivity of a pristine PEDOT:PSS film of about 1.5 S/cm. The conductivity can be tuned by adding a varying amount of phenylalanine in PEDOT:PSS. By further processing these composite films by treating them with methanol followed by annealing, conductivity of over 2200 S/cm can be achieved. In addition to increased conductivity, the composite films also have higher optical transmissivity compared to a native PEDOT:PSS polymer film with the composite thin film achieving transmittance of over 97%.

Abstract: Improved electrically conductive pili were generated from a natural pilus protein from the microorganism Geobacter sulfurreducens. Substituting a tryptophan for the phenylalanine at position F51 and a tryptophan for the tyrosine at position Y57 of the pilus monomer substantially increased the conductivity of the pili and reduced their diameter to 1.5 nm. Substantial improvements in conductivity were also achieved by substituting an additional tyrosine, histidine, and phenylalanine in the pilus monomer to mimic the monomer of Geobacter metallireducens, but the pili retained the typical Geobacter sulfurreducens wild-type diameter of 3 nm.

Abstract: Improved electrically conductive pili were generated from a natural pilus protein from the microorganism Geobacter sulfurreducens. Substituting a tryptophan for the phenylalanine at position F51 and a tryptophan for the tyrosine at position Y57 of the pilus monomer substantially increased the conductivity of the pili and reduced their diameter to 1.5 nm. Substantial improvements in conductivity were also achieved by substituting an additional tyrosine, histidine, and phenylalanine in the pilus monomer to mimic the monomer of Geobacter metallireducens, but the pili retained the typical Geobacter sulfurreducens wild-type diameter of 3 nm.