近年来对作为典型的硝基苯环类炸药的三硝基甲苯(TNT)的痕量检测受到越来越多的关注。将银胶纳米颗粒作为表面增强拉曼散射(SERS)基底,研究了10-6 mol.L-1的TNT的表面增强拉曼光谱的优化实验条件,重点研究了氯化钠溶液(NaCl)的含量以及碱性水解对TNT的表面增强拉曼光谱的影响。实验发现SERS样品中如果没有加入NaCl溶液,将观察不到TNT的SERS谱。加入的NaCl的含量必须在某一个范围之内才能观察到TNT的SERS谱,而且在这个范围之内,随着NaCl含量的增加,TNT的1 392cm-1处的拉曼峰出现先增大后减小的现象。对NaCl在TNT的SERS中的作用给予了理论解释。研究还发现TNT分子经过碱性水解后,与银纳米颗粒之间的吸附作用增强,其SERS谱的强度明显优于未经碱性水解的SERS结果。
Trinitrotoluene(TNT),a representative nitroexplosive,attracts more and more attentions because of the urgent demand for trace analysis of explosives in recent years.The present study investigated the experiment condition of the surface enhanced Raman scattering(SERS) of 10-6 mol·L-1 TNT solution,especially the influence of NaCl and basic hydrolysis.The results indicate that SERS spectra of TNT can not be obtained when preparing the SERS samples without NaCl,and it was also shown that the intensity of Raman peaks has a relationship with the concentration of NaCl.With the increase in the concentration of NaCl,the intensity of Raman peak at 1 392 cm-1 has a maximum value.This report explained the reason why NaCl can affect the intensity of SERS theoretically.It was also shown that the SERS spectrum of TNT treated with basic hydrolysis is more intense than that without basic hydrolysis.