STUDY ON ENHANCED RAMAN SCATTERING OF SILVER SURFACE ROUGHENED WITH HNO3

Silver surfaces producing enhancement of the Raman scattering for adsorbed molecules have been simply prepared by etching them in HNOsolution. The dependence of the enhancement on etching time at different concentrations of the etching solution has also been investigated. When etched with 2.5 mol/L HNOfor 10-20 min, silver surfaces can all produce strong enhancement, and the surface-enhanced Raman scattering (SERS) activity can survive for more than 10 h in air. For Kr~+ laser excitation at 647.1 nm, the observed surface