Metal nanoshell assembly on a virus bioscaffold

Chilo iridescent virus is demonstrated as a useful core substrate in the fabrication of metallodielectric, plasmonic nanostructures. A gold shell is assembled around the wild-type viral core by attaching small, 2-5-nm gold nanoparticles to the virus surface by means of the chemical functionality found inherently on the surface of the proteinaceous viral capsid. The density of these nucleation sites was maximized by reducing the repulsive forces between the gold particles through electrolyte addition. These gold nanoparticles then act as nucleation sites for the electroless deposition of gold ions from solution around the biotemplate. The optical extinction spectra of the metalloviral complex is in quantitative agreement with Mie scattering theory. Overall, the utilization of a native virus and the inherent chemical functionality of the capsid afford the ability to grow and harvest biotemplates for metallodielectric nanoshells in large quantities, potentially providing cores with a narrower size distribution and smaller diameters (below 80 nm) than for currently used silica.