Scientists have discovered that hair-like filaments on the surface of Geobacter bacteria exhibit electrical conductivity comparable to that of copper, paving the way for the employment of biological materials in nanoscale electron devices. Scientists from the University of Massachusetts at Amherst used X-ray diffraction to analyse the structure of the filaments called the pili.
They found that the electronic arrangement and small molecular separation distances of less than 0.3 nanometres give the pili an excellent conductivity. Although proteins are usually electrically insulating, the researchers said the study supports the concept that the pili of G. sulfurreducens represent a novel class of electronically functional proteins in which aromatic amino acids promote long-distance electron transport.
The research findings, published recently in the journal mBio, can provide useful feedback for studies targeting the enhancement of pili’s electrical conductivity through genetic engineering. It could subsequently be used to construct low-cost, non-toxic, nanoscale, biological sources of electricity for light-weight electronics and for bioremediation.