Surface Enhanced Raman Scattering from copper nanoparticles obtained by laser ablation

Copper colloidal nanoparticles are obtained by laser ablation in aqueous solutions of ligands by nanosecond laser pulses at 532 and 1064 nm and examined by localized surface plasmon resonance (LSPR) and surface-enhanced Raman scattering (SERS) spectroscopy, along with transmission electron microscopy (TEM) and zeta potential measurements. This fabrication method, besides providing SERSactive substrates without spectral interferences of reagents, as it generally occurs for the chemical reduction of metal ions, allows obtaining colloidal suspensions which are stable in time because the copper particles are capped by ligand molecules as long as they are formed by laser ablation. This prevents aggregation among metal nanoparticles and probably reduces overall oxidation of the copper surface.