自组装银纳米粒子及其SERS增强效应

采用柠檬酸三钠还原硝酸银方法制备出银纳米粒子, 并通过在玻璃表面修饰3-氨基丙基-三乙氧基硅烷( APTES)对银纳米粒子进行自组装。利用紫外-可见(UV-Vis)吸收光谱和扫描电子显微镜(SEM)测试手段对样品进行分析和表征。由测试结果可知银纳米粒子的尺寸比较均匀, 组装致密度较高, 基本以亚单层的形式分布于基底表面。进一步研究了以结晶紫(CV)为探针分子的自组装基底的表面增强拉曼光谱(SERS), 计算发现该基底的拉曼增强因子数量级达106。结果表明: 银纳米粒子自组装基底具有良好的SERS增强效应, 为痕量CV的检测提供了有效的方法。

Self-Assembly of Ag Nanoparticles and Its SERS-Effect

High density and uniform surface enhanced Raman spectroscopy(SERS) substrates are obtained using self-assembly Ag nanopartices on the surface of transparent glass modified with 3-aminopropyltrimethoxysilane(APTES),where the Ag nanoparticles were synthesized by aqueous reduction of AgNO3 with trisodium citrate.Surface morphology of thin films with assembled silver nanoparticles is studied with UV-Vis spectroscopy and SEM.Using crystal violet(CV) as probe molecule,Raman spectra of CV on self-assembled Ag nanopartices substrate are taken.Experimental results indicate that silver particles with uniform diameter and high density were assembled as a sub-monolayer.Raman spectra are enhanced with an enhancement factor of about 106,which means that the self-assembled Ag nanopartices substrate has an excellent SERS-activity.Such substrate can provide an effective way to detect the toxic CV molecules.