为实现表面增强拉曼散射(SERS)信号的快速检测分析, 报道了一种简单的利用SiO2包覆对巯基苯甲酸(4MBA)修饰的Ag纳米粒子形成核壳结构纳米颗粒SERS标记物的方法。通过调控溶液中硝酸钠的浓度来控制4MBA-Ag的聚集程度, 获得不同的“热点”效应, 然后利用SiO2包覆实现对聚集体的固定。扫描电镜结果证实此种方法非常有效。该体系中SERS的信号强度依赖于4MBA-Ag的聚集程度。该研究结果有助于实现聚集体SERS标记物在生物成像、检测和传感等方面的应用。

In order to realize the unltrasensitive analysis by using the surface enhanced Raman scattering (SERS), we presented a simple and reproducible approach to encapsulate the aggregation of 4-mercaptobenzoic acid-modified Ag nanoparticles with silica. In order to obtain “hot spot”, the level of aggregation could be controlled by varying the concentration of NaNO3, and then the aggregation was coated with silica, which was demonstrated with SEM. In conclusion, the SERS signal seriously depended on the level of aggregation. Due to the strong enhancement effect, this technique has the potential in biomedical field.