After preparing Pt nanoparticles by laser ablation in distilled water, centrifugation was repeatedly applied to obtain nanoparticles with sizes greater than similar to15 nm. Surprisingly, platinum aggregates composed of similar to17 nm Pt nanoparticles on silicon wafer or ITO exhibited fairly strong surface-enhanced Raman scattering such that the enhancement factor for benzenethiol adsorbed thereon, for instance, could reach values as large as 200 with 514.5 nm excitation. (C) 2004 Elsevier B.V. All rights reserved.