SERS Spectroscopy Used To Study an Adsorbate on a Nanoscale Thin Film of CuO Coated with Ag

In this work, 5, 15, and 30 nm Ag island films over CuO thin films (AgFOCuF) were prepared as SERS substrates. The spectra of 4-mercaptopyridine (4-Mpy) adsorbed on these AgFOCuF and bare Ag island films are compared. The Raman spectrum of a bare 5 run Ag island film is weak. However, the Raman signal of 4-Mpy from 5 nm AgFOCuF substrate is enhanced and can be readily ascribed to Surface plasma resonance of silver and charge transfer between the silver and CuO nanoparticles. Moreover, the difference between the spectra of 4-MPY adsorbed on CuO film partially covered with Ag island film and CuO film entirely covered with Ag film confirms that the observed Raman scattering arises from the interaction between CuO film and Ag island film.