Bioscaffolds for metal nanostructures

The use of virus nanoparticles, specifically Chilo and Wiseana Iridovirus, as core substrates in the fabrication of metallodielectric, plasmonic nanostructures is discussed. A gold shell is assembled around the viral core by attaching small, 2 - 5 nm, gold nanoparticles to the virus surface by means of inherent chemical functionality found within the protein cage structure of the viral capsid. These gold nanoparticles act as nucleation sites for electroless deposition of gold ions from solution. The density of the gold nucleation sites on the virus was maximized by reducing the repulsive forces between the gold particles, which was accompolished by controlling the ionic strength of the nanoparticle solution. UV/Vis spectroscopy and transmission electron microscopy were used to verify creation of the virus-Au particles. The optical extinction spectra of the metallo-viral complex were compared to Mie scattering theory and found to be in quantitative agreement.