Formation of small gold clusters in solution by laser excitation of interband transition

Gold nanoparticles with ∼10 nm in average diameter were prepared by laser ablation of a gold metal plate in an aqueous solution of sodium dodecyl sulfate (SDS) and were fragmented by excitation of an interband transition of gold nanoparticles under irradiation of an intense 355-nm pulsed laser. Fragmentation dynamics was investigated by comparing the fragmentation by excitation of a surface plasmon band of gold nanoparticles by a 532-nm laser. It is found that gold nanoparticles with 1.5-nm average diameter are produced together with small gold clusters by properly optimizing the surfactant concentration.