Active site-dominated electromagnetic enhancement of surface-enhanced Raman spectroscopy (SERS) on a Cu triangle...

Revealing the sensitivity and selectivity of the Raman enhancement mechanism is extremely significant for disease diagnosis, environmental surveillance, and food safety supervision. In this study, chemical erosion copper triangle plates (CTPs) were employed as SERS substrate to detect the rhodamine B (Rh B) probe molecule at different etching times. A simple and cost-effective method affords unique insights into the surface enrichment of analytes, which could facilitate the high-performance SERS analysis of numerous analytes. The relationship between the Raman intensity and the concentration of Rh B follows the Freundlich model, which means that the wet-etching surface can create SERS-active site attachment Rh B molecules on the CTPs. The morphology of CTPs was modified by H₂O₂/HCl etchants; however, the composition of CTPs remained stable without oxidation. This proposes that the largest contribution to the enhancement was the hot-spots that can produce surface plasma resonance on the CTPs. The number of hot-spots can be intelligently adjusted by the artificial control of the surface morphology of metal materials, providing an unambiguous improvement in the SERS sensitivity and capability.