Impact of adsorbed molecules on the relative intensity of surface-enhanced Raman scattering

作者：Hongbo Jing, Lei Chen, Xin Yue, Zhen Gong, Ronghui Xu, Chenxi Wan, Ruiqin Zhang, Zhigang Wang · 发表于：Physical review. B./Physical review. B · 年份：2025 · DOI：10.1103/physrevb.111.075430 · 被引用次数：6 · 研究领域：Gold and Silver Nanoparticles Synthesis and Applications、Spectroscopy Techniques in Biomedical and Chemical Research、Nanocluster Synthesis and Applications

Surface-enhanced Raman scattering (SERS) enhances molecules' vibrational signals for single-molecule detection which correlates with light-induced polarizability variations. The involved charge-transfer process impacts molecular polarizability, offering efficient modulation methods for SERS. Herein, the effect of ambient molecules $({\mathrm{H}}_{2}\mathrm{O},$ ${\mathrm{CO}}_{2}, \text{and} {\mathrm{N}}_{2})$ on the SERS spectra of a metal-pyridine (Py) system is explored. It is found that the relative intensity changes differently between vibrational modes when adsorbing different ambient molecules. Especially, ${\mathrm{CO}}_{2}$ adsorption alters the intensity ratios between ring-breathing and ring-stretching modes in Py molecule. Further polarizability analysis shows that ${\mathrm{CO}}_{2}$'s larger polarizability contribution and adsorption configuration lead to the dominating ring-breathing mode. Additionally, SERS enhancement reduces with increasing ambient molecules, due to weakened electron exchange between Py and metal substrate. This study has the potential to provide an insight into detecting relative intensity changes in SERS and promote the development of related applications.