Tunable SERS Platforms from Small Nanoparticle 3D Superlattices: A Comparison between Gold, Silver, and Copper.

Herein we present new substrates for surface-enhanced Raman spectroscopy (SERS). The synthesis of colloidal nanoparticles through an organometallic route allowed us to obtain gold, silver, or copper nanoparticles with well-controlled shapes and sizes (5-12 nm in diameter). The organization of these nanoparticles into large-scale 3D superlattices produces a very large number of "hot spots" at the origin of the signal enhancement.