Synthesis of novel nanodiamonds - gold core shell nanoparticles

This work presents novel diamond-based nanostructures formed by a fluorescent nanodiamond core coated with a gold shell (ND@Au). Gold shell was grown on silicon-doped nanodiamonds in water by controlled reduction of gold chloride. The resulting gold-coated nanodiamond samples were characterized by means of scanning electron microscopy, UV-visible, Raman and luminescence spectroscopies. These gold-coated nanodiamonds showed a strong resonance absorption in the visible and near-infrared (NIR) range. When excited with green laser, the silicon doped nanodiamonds emit a stable fluorescence peaked at about 740 nm due to the SiV centers with no photobleaching and photoblinking. In this work we demonstrate that optical properties of the silicon-doped nanodiamonds are retained after the formation of the gold shell.