提出一种新型的荧光及表面增强拉曼散射(SERS)双模式光学纳米探针。首先, 通过再沉淀-包覆法合成二氧化硅包覆香豆素6的纳米颗粒, 再在二氧化硅表面静电吸附多聚赖氨酸分子形成包覆层, 随后通过原位还原的方法在多聚赖氨酸壳层复合银纳米颗粒, 最后在银纳米颗粒表面吸附拉曼分子即形成双模式纳米探针。该探针通过二氧化硅包覆的荧光分子产生荧光信号, 以多聚赖氨酸表面的银纳米颗粒作为SERS增强基底, 利用拉曼分子获得SERS信号, 实现了荧光及SERS 双模式成像。荧光与表面增强拉曼散射相结合的双模式分析技术可同时发挥二者的优点, 提高成像的分辨率和灵敏度, 在生物医学领域具有重要的应用价值。

A novel type of dual-mode optical nanoprobe combining fluorescence and surface enhanced Raman scattering was described. Firstly, the fluorescent nanoparticles doped with coumarin 6(C6) and coated with silica were prepared by a reprecipitation-encapsulation method. Then, PLL molecules were electrostatically absorbed onto the surface of negatively charged NPs. Subsequently, the silver nanoparticles were attached to the surface of PLL shell by the in-situ reduction. Finally, Raman molecules were connected on the silver nanoparticles surface. The fluorescent signal in this probe derives from the fluorescent molecular C6. The silver nanoparticles are used as the enhanced substrate of SERS, and the SERS signal is from Raman molecules. The double-mode analysis technique, combining fluorescence and surface enhanced Raman scattering, possesses high resolution and sensitivity of imaging, and is promising in the biomedical field.