Multi-functional, thiophenol-based surface chemistry for surface-enhanced Raman spectroscopy

Surface-enhanced Raman spectroscopy (SERS) has been recognized as one of the most sensitive sensing technologies and has been used for a variety of chemical, biological and medical applications. Compared to traditional direct SERS detection using a bare metal SERS-active substrate, surface chemistries and surface modifications on SERS-active substrates are becoming more and more important to achieve the detection of target analytes with a small surface affinity or weak Raman activity. As one special class of surface chemistries and modifications for SERS-active substrates, the thiophenol-based molecules offer new functions, increased sensitivity, and improved specificity to SERS-based sensing. The thiol group helps to form a stable modification on the gold or silver surface of SERS-active substrates, the benzene ring is used to report and amplify the detection signal, and the specific functional group on each thiophenol-based molecule contributes to the detection specificity. This article highlights the recent advances in thiophenol-based surface chemistry for SERS applications. The use of thiophenol-based molecule modified SERS-active substrates for fundamental studies, surface catalysis investigations and chemical and biological sensing is comprehensively discussed.