Surface-enhanced Raman scattering of p-hydroxybenzoic acid in pure Ag colloids produced by laser ablation

'Chemically pure' Ag colloids were prepared by laser ablation of Ag plate in pure water. The Ag colloids have good stability and the Ag nanoparticles in the colloids have homogeneous size distribution. Compared with the Ag colloids produced by chemical reduction methods, there was no any extraneous component ions in the colloids produced by laser ablation. Synchronously, we obtained much higher quality SERS spectra of PHBA molecules in the Ag colloids produced by laser ablation, the study of the adsorption behavior of p-hydroxybenzoic acid (PHBA) in the Ag colloids by surface-enhanced Raman scattering (SERS) indicated that the Ag colloids system was highly efficient substrate for SERS investigation.