本论文实验应用柠檬酸盐还原硝酸银 –Lee and Meisel（C-M）法制备银溶胶，得到了粒径大多处于70nm的银纳米粒子。利用扫描电子显微镜（SEM）对不同反应过程中的粒子和反应完全生长后的大粒径纳米粒子进行表征，对生长机理进行了分析。SEM图像中都是灰度均一的纳米粒子，在反应过程初期的粒子，外部可以看到清晰的膜状包裹结构。随着时间的延长，还原反应持续进行，待反应时间持续到1小时左右时，得到分布较为均匀的纳米银溶胶样品。 分别以碱性品红（BF）、结晶紫（CV）以及爆炸物质三硝基甲苯（TNT）作为探针分子研究了激发波长532nm下，银纳米粒子上的表面增强拉曼散射光谱（SERS）。可以检测各探针分子稀释到浓度为10-9M水溶液的明显拉曼增强峰，讨论了不同条件下银溶胶的配置以及效果。银纳米粒子和BF、CV以及TNT发生的吸附作用明显，TNT的SERS主要振动峰与固体相比略有不同，不同pH值的TNT溶液所呈现出的SERS峰有着明显的区别，由于银纳米粒子的表面增强效果，基于SERS的TNT最低检测限达到了10-9M。

In this thesis,Ag colloid have been synthesized by Lee and Meisel (C-M) method,the size of nanoparticles are around 70nm. SEM was used to characterize Ag nanoparticle in different growing time,the results were analysed. In SEM pic, nanoparticles all looked grayness . Membranes were observed around those nanoparticles which reacted in short time.As time increased,reaction was progressing. When reaction lasted about 1 hour, the sample were solid nanoparticles with a uniform distribution. Using Basic Fuchsin(BF) , Crystal Violet(CV) , and explosive 2,4,6-Trinitrotoluene (TNT) as probe to get the SERS spectrue on Ag colloid substrate.The wavelength of laser power was 532nm,all the apparent probe's SERS spectrue under low concentration of 10-9M were gotted.Different condition when synthesizing Ag colloid and their effect were discussed.There were obvious adsorption between Ag colloid and probe molecule.Slight Raman shift move was observed comparing the TNT SERS spectrum and solid TNT Raman spectrum,huge Raman peak change between TNT SERS spectrum under different pH condition . Since Ag nanoparticle has good enhanced effect, our limit detection of aqueous TNT was 10-9M.