通过改进Lee和Meisel法, 制备了两种银胶。以三聚氰胺分子为探针分子, 银胶为SERS基底, 使用便携式拉曼光谱仪进行拉曼测试。拉曼光谱表明银纳米粒子和三聚氰胺发生的吸附作用明显, 三聚氰胺的四个较强振动峰有4~9 cm-1的频移和强度比变化较大。由于SERS基底的表面增强作用, 三聚氰胺的便携式拉曼光谱仪最小检测量达到了6×10-12 g, 实现了三聚氰胺的亚单分子层检测水平。该检测方法快捷、简便, 如果结合奶粉或食品中三聚氰胺的固相萃取技术, 将可以应用于三聚氰胺的现场、快速、半定量检测。

Silver colloid was synthesized using improved traditional silver colloid method. Melamine was used as probe molecular, colloid as SERS substrate. A portable Raman spectrometer was used to do Raman test. The results showed that the adsorption of melamine on silver nanoparticle is significant, which caused Raman shift by 4~9 cm-1 and intensity ratios difference of the four highest vibration of melamine. With the surface enhancement of silver colloid, the minimum detectable amount of melamine reaches 6×10-12g. The detection of sub-monomolecular layer level of melamine was obtained with the use of surface enhanced Raman scattering. This detection method is sensitive fast and simple. If combined with solid phase extraction technology of melamine in milk powder or food, this method can be applied to on-site, rapid, semiquantitative detection of melamine.