Silver Clusters onto Nanosized Colloidal Silica as Novel Surface-Enhanced Raman Scattering Active Substrates (original) (raw)

A new method is proposed for obtaining surface-enhanced Raman scattering (SERS)-active substrates by photochem ical reduction of silver nitrate onto colloidal silica. Transmission electron microscopy (TEM ) and UV-visible absorption spectroscopy are employed to investigate the nanoscale structure of the materials. H igh quality SERS spectra are obtained from different organic ligands to check the ef ciency of these substrates. A marked stability of the colloidal suspension is ensured by the scarce tendency of the Ag-doped silica particles to aggregate by either aging or adsorption of ligand.