Some Progresses in Mechanistic Studies on Surface-Enhanced Raman Scattering

In order to further develop surface-enhanced Raman spectroscopy to a versatile and ultra-sensitive diagnostic tool for surface, analytical, life and materials sciences, it is highly desirable to comprehensively reveal the mechanism of surface-enhanced Raman scattering(SERS). In this review article, emphasis is put on recent work of our group on the chemical enhancement (CE) mechanism. Three types of CE are classified as be enhancement by chemical-bonding, surface complex or photo-induced charge transfer. The electromagnetic (EM) field enhancement mechanism will then be introduced briefly, although it is to be considered the major contribution to SERS. Finally, a prospect of establishing the unified theory, that combines the CE and EM mechanism, will be discussed.