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通过在硅片上修饰聚乙烯吡咯烷酮(PVP)对银纳米粒子进行组装,得到均一的表面增强拉曼光谱(SERS)基底。借助于此基底,在水溶液环境中,以异烟酸(INA)和罗丹明6g(R6g)作为探测分子,研究了氯离子(Cl-)对SERS增强的影响。结果表明,对于不同的探针分子,Cl-对银颗粒SERS活性的影响存在选择性。对于INA分子,在溶液中没有Cl-的情况下,分子通过羧基以锐角吸附在银颗粒表面,具有良好的SERS谱。在加入Cl-后,由于竞争吸附,INA分子脱附,SERS信号消失。R6g分子在银颗粒表面没有特异吸附,Cl-的加入并没有影响其与银颗粒的作用状态,在加入Cl-后SERS光谱没有发生显著变化。
The silver nanoparticle was assembled by modifying polyvinylpyrrolidone (PVP) on silicon wafer to obtain a uniform surface enhanced Raman spectroscopy (SERS) substrate. With this substrate, the effect of chloride ion (Cl-) on the enhancement of SERS was studied in an aqueous environment using isonicotinic acid (INA) and rhodamine 6g (R6g) as probe molecules. The results show that, for different probe molecules, Cl- has a selective effect on the SERS activity of silver particles. For the INA molecule, in the absence of Cl- in the solution, the molecule adsorbed on the silver particle surface through the carboxyl group at an acute angle with a good SERS spectrum. After addition of Cl-, the SERS signal disappears due to adsorption of INA molecules by competitive adsorption. The R6g molecule has no specific adsorption on the surface of silver particles. The addition of Cl- did not affect the interaction between R6g molecules and the silver particles. There was no significant change of SERS spectra after adding Cl-.