壳聚糖包裹AgInS_2的物理表征及生物毒性研究

选用天然多糖中唯一的碱性多糖——壳聚糖作为稳定剂和包裹剂,成功合成了水溶性的Ag In S2量子点/低分子量壳聚糖纳米复合材料(Ag In S2/LCSMS)。利用透射电子显微镜(TEM)、FT-IR傅里叶红外光谱仪、紫外吸收光谱、荧光分光光度计等表征手段对纳米复合材料的形貌、化学组成及光学性质进行了研究。结果表明,Ag In S2/LCSMS纳米复合材料的粒径约为5~6 nm,在水相中仍具有较稳定的发光。之后,对Ag In S2/LCSMS纳米复合材料的生物相容性进行了研究,对比Ag In S2/LCSMS纳米复合材料与Ag In S2量子点的细胞活性测试结果发现,Ag In S2/LCSMS纳米复合材料的细胞活性比Ag In S2量子点有了明显的提高,说明通过低分子量壳聚糖的包裹可以明显提高纳米材料的生物相容性。因此,这类具有较好水溶性和生物相容性的荧光Ag In S2/LCSMS纳米复合材料可作为优良的生物荧光标记材料在生物医学检验、细胞以及活体成像研究中有广泛的应用前景。

Physical Characterization and Biological Toxicity of Chitosan-capped AgInS2 Quantum Dots

The water-soluble AgInS₂ quantum dots/low molecular weight chitosan nanocomposites (AgInS₂/LCSMS) were successfully synthesized. Natural polysaccharide in alkaline polysaccharide--Chitosan was used as stabilizer and capped agent. The structure, chemical composition, and optical properties of AgInS₂/LCSMS nanocomposites were studied by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), fluorescence microscope, fluorescence spectrophotometer, and UV-Vis absorption spectroscopy, etc. The results show that the particle diameter of AgInS₂/LCSMS nanocomposites is about 5-6 nm, and they are still have a relatively stable luminescence in the water phase. In addition, we studied the biological compatibility of the AgInS₂/LCSMS nanocomposites. Compared with pure AgInS₂ quantum dots, the cell activity of AgInS₂/LCSMS nanocomposites has an obvious improvement. It shows that low molecular weight chitosan wrapping can obviously improve the biocompatibility of the nanometer materials. Therefore, this kind of AgInS₂/LCSMS fluorescent nanocomposites with good water solubility and biological compatibility show significant value for potential applications in biomedicine test, biolabel, cell and in vivo imaging studies.