本文研究了核壳结构CdS-TiO2纳米颗粒光对HL60细胞光催化灭活作用, 并初步探讨了CdS量子点增强TiO2光催化灭活效率的作用机理。实验利用超声法制备了核壳结构CdS-TiO2纳米颗粒, 使用CCK-8法检测了其对白血病HL60细胞的光催化灭活效果, 并采用活性氧分析和荧光发光光谱等分析手段对CdS量子点增强TiO2光催化灭活效率的作用机理进行了分析。细胞实验结果表明, 在暗室条件下, 随着CdS包裹的TiO2外壳的增厚, 细胞的暗室存活率从28.5%逐渐上升至80%; 在可见光照下, 细胞的存活率显著下降。CdS-TiO2纳米颗粒对HL60细胞的光催化灭活率均超过60%, 其中CdS-TiO2样品0.6对HL60细胞的光催化灭活效率最高, 达到95%。根据荧光光谱和活性氧含量分析的结果推测, 这可能是由于核壳结构的CdS内核与TiO2外壳之间产生了有效的电子转移, 抑制了TiO2的空穴电子的复合, 增强了TiO2外壳的光催化活性, 最终增加了TiO2对HL60细胞的PDT灭活效果。

The photocatalytic inactivation of core-shell cadmium sulfide-titanium dioxide nanoparticles (CdS-TiO2 nanoparticles) on HL60 cells and its mechanism were researched in this paper．Core-shell cadmium sulfide-titanium dioxide (CdS-TiO2) nanoparticles were synthesized by ultrasonic method. The photocatalytic inactivation of these core-shell nanoparticles on HL60 cells were analyzed by CCK-8 assay. Its mechanism were investigated using reactive oxygen species (ROS) generation and fluorescence emission spectrum analysis．Results of cell experiment showed that, in comparison with the cell group of CdS, viability of cells treated with CdS-TiO2 increased from 28.5% to 80%, with the increment of TiO2 shell thickness in the darkroom conditions. However, under light exposure, their viability decreased sharply. More than 60% cells were killed in each group treated by CdS-TiO2. Among these samples, cell groups treated by CdS-TiO2 sample 0.6 showed the highest cell inactivated efficiency of 95%. According to the results of ROS generation and FS analysis, it could be concluded that the existence of CdS resisted the recombination of photo-induce holes and electrons, enhancing the photocatalytic activity of TiO2 shell and eventually resulting in superior cell killing effect.