Physics (Internal)

"Electrically Conductive Protein Nanowires: A Revolutionary Electronic Material"

This event is part of the Biophysics Seminars. 12:30PM.

Geobacter, a common soil microorganism, produces electrically conductive protein nanowires that have a diameter of 3 nm and are 10-30 µm long. Geobacter uses its nanowires to make electrical connections with other microbial species and minerals. This finding has led to new concepts for the function of microbial communities and new practical applications for electroactive microorganisms. More recently, it has been demonstrated that the properties of the Geobacter protein nanowires can be modified with simple genetic techniques. These electrically conductive synthetic protein nanowires (e-SPNs) can be modified to tune conductivity over a broad range; to change the nanowire width; and to add peptide linkers for sensing applications. e-SPNs are attractive as an electronic material because they can be produced from renewable feedstocks and are biodegradable, yet they are also highly robust for device fabrication. Proof-of- concept studies have demonstrated that e-SPNs can be incorporated into polymers to produce conductive composite materials and can be assembled into “tapes” and “cables”. e-SPNs have many potential advantages over other nanowire materials for the development of nanowire-based sensors. The dynamic sensing capabilities of sensors fabricated with e-SPNs have been demonstrated in proof-of-concept studies designed to produce wearable sensors. Multiple lines of experimental evidence suggest that e-SPNs have a metallic-like conductivity that can be attributed to overlapping π-π orbitals of aromatic amino acids. However, more basic information on the structure of e-SPNs, mechanisms for electron transport, and other electronic properties is required in order to guide the design of e-SPNs for applications as electronic components.