本文采用共沉淀法制备了L-半胱氨酸（L-Cys）修饰的Fe₃O₄包裹TiO₂（Fe₃O₄@TiO₂/LCys）复合纳米粒子。通过透射电子显微镜（TEM），X射线衍射（XRD）和傅立叶变换红外光谱仪（FTIR）对复合纳米粒子进行了表征，并讨论了复合纳米粒子对HL60细胞体外光动力疗法（PDT）灭活的影响。并对其PDT灭活机制进行了初步探索。试验表明，Fe₃O₄@TiO₂/LCys复合纳米粒子分散性高，生物相容性好，对细胞的暗毒性更低，并可以有效增强靶向性，提高PDT灭活效率，在410 nm波长的光激发下，光照剂量为18 J/cm²的情况下，当TiO₂与Fe₃O₄的比例为1:3 时，整体PDT效率最高。PDT灭活效率可达69.36%。

In this paper, L-cysteine (L-Cys) modified  Fe₃O₄coated titanium dioxide (Fe₃O₄@TiO₂/L-Cys) composite nanoparticles were prepared by coprecipitation method.The composite nanoparticles were characterized by transmission electron microscopy (TEM), Xray  diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The effects of composite nanoparticles on PDT inactivation of HL60 cells in vitro were discussed.The inactivation mechanism of PDT was preliminarily explored. The results showed that Fe₃O₄@TiO₂/L-Cys composite nanoparticles had high dispersibility, good biocompatibility, lower dark toxicity to cells, and could effectively enhance the targeting and improve the inactivation efficiency of PDT. When the irradiation dose was 18 J/cm2 at 410 nm, the overall PDT efficiency was the highest when the ratio of titanium dioxide to Fe₃O₄@TiO₂was 1:3. The PDT inactivation efficiency of Fe₃O₄@TiO₂/L-Cys was 69.36%.