Prions Form Templates for Nanometer Circuits

Researchers have used prions, misfolded proteins that are extremely stable under most conditions, as the matrix upon which to cast nanometer-sized gold and silver electrical circuits.

A study published April 2, 2003, in the online edition of the Proceedings of the National Academy of Sciences, describes their novel technique for using amyloid protein fibers produced naturally by prions isolated from the yeast Saccharomyces cerevisiae.
The prions produced 10-nm-wide protein fibers that were stable under a wide variety of harsh physical conditions. Their lengths could be roughly controlled by assembly conditions in the range of 60 nm to several hundred micrometers.

The protein fibers contained surface-accessible cysteine residues that were used to covalently bind colloidal gold particles. These fibers were then placed across gold electrodes, and additional metal was deposited by highly specific chemical enhancement of the colloidal gold by reductive deposition of metallic silver and gold from salts. The resulting silver and gold wires were approximately100 nm wide. These biotemplated metal wires demonstrated the conductive properties of a solid metal wire, such as low resistance and ohmic behavior.

"Most of the people working on nanocircuits are trying to build them using 'top-down' fabrication techniques used in conventional electrical engineering,” explained senior author Dr. Susan Lindquist, director of the Whitehead Institute (Cambridge, MA, USA; www.wi.mit.edu). "We thought we would try a 'bottom-up' approach, and let molecular self-assembly do the hard work for us. In all important respects, these nanowires possess the characteristics of conventional solid metal wire such as low resistance to electrical current. With materials like these, it should be possible to harness the extraordinary diversity and specificity of protein functions to nanoscale electrical circuitry.”



Related Links:
Whitehead Institute for Biomedical Research