Abstract:A new photosensitizer 5ALATSFA was synthesized through the combination of cancer targeting molecule folate (FA), silica coated TiO2 (TS) nanoparticles and 5aminolevulinic acid (5ALA). Photodynamic therapy efficiency of 5ALATSFA on leukemia HL60 cell was studied in this paper. The composite nanoparticles (5ALATSFA) was synthesized by surface modification method and was characterized by transmission electron microscope (TEM), fourier transformation infrared spectrum (FTIR), ultravioletvisible absorption (UVVis) and so on. HL60 cells were cultured with different concentrations of composite nanoparticles 5ALATSFA for 12 h. The dark toxicity and PDT inactivation effect of nanoparticles were detected by Cell Counting Kit8 (CCK8) method. The experimental results show that the dispersibility of 5ALATSFA composite nanoparticles is good. When 5ALATSFA is incubated with HL60 cells for 12 hours at a concentration of 100 μg/mL, the dark toxicity of 5ALATSFA to HL60 cells is low and the 5ALATSFA inactivation efficiency of photodynamic therapy can reach 74.65%, which is significantly higher than that of TiO2 and TSFA. Therefore, 5ALATSFA has a good prospect of application as a potential photosensitizer.