金纳米棒核／二氧化硅壳纳米复合结构的可控制备及细胞成像

采用模板合成以及溶胶凝胶方法制备了金纳米棒核／二氧化硅壳（GNR@SiO2）纳米复合粒子，探讨了这种新型纳米复合结构的可控制备、光谱性质、细胞毒性和细胞成像。通过紫外可见分光光度计、透射电镜、共聚焦显微镜对样品进行表征，结果表明：通过对反应时间的调控，获得的纳米复合粒子的二氧化硅壳层厚度可以控制在20～30nm。由于二氧化硅壳层的存在，大大提高了金纳米棒的稳定性，同时降低了金纳米棒的细胞毒性；此外，由于二氧化硅壳层具有良好的化学修饰作用，因此可以将荧光探针分子标记在二氧化硅壳层表面，修饰后的纳米复合粒子可以通过细胞内吞作用进入细胞，从而实现细胞内的光学成像。因此，该纳米粒子复合材料在生物传感、细胞成像以及光热治疗等方面有着良好的应用前景。

Controlled synthesis and cell imaging of gold nanorod-silica core-shell nanoparticles

The template method and sol-gel technique were used for the preparation of gold nanorod-silica core-shell （GNR@ SiO2 ） nanocomposites. The controllable synthesis, spectroscopic properties, cytotoxicity and cell imaging of these nanocomposites were discussed by using UV-Vis spectrophotometry, transmission e-lectron microscopy, confocal microscopy and other characterized measurements. The results show that, by con-trol of the reaction time, the thickness of silica shell can be facilely tuned in the regime of 20 - 30 nm ; the colloidal stability of gold nanorods has been greatly improved, and their cell cytotoxicities are significantly de-creased due to the presence of the silica shell. In addition, fluorescent probes can be easily attached on the silica shell by post chemical reactions. As formed fluorescent core-shell nanocomposites can be easily captured by cells through endocytosis pathway, which is useful for the optical imaging. Therefore, these nanoparticle composites have a great potential in fields of biosensors, cell imaging and photothermal therapy.