Characterization of the copper surface optimized for use as a substrate for surface-enhanced Raman scattering

A new electrochemical procedure of roughening of a copper surface was developed, producing a surface with a high Ž . surface-enhanced Raman scattering SERS activity. The surface morphology and composition was characterized by energy dispersiverwavelength dispersiverX-ray microprobe analysis and compared to the Cu electrodes roughened by the commonly used oxidation–reduction reactions. The morphology of such a surface was completely different from those produced by traditional electrochemical procedures. Moreover, X-ray microprobe analysis revealed that our new surface remained unoxidized in contrast to the other SERS active Cu surfaces. The potential profiles of SERS intensity of the ring Ž . breathing mode of pyridine adsorbed on these surfaces were discussed and interpreted in terms of charge-transfer CT effect. q 1998 Elsevier Science B.V.