Objective: To prepare cerium doped carbon quantum dots (Ce-doped CDs) with efficient photothermal ablation for the photothermal treatment of breast cancer cell. Methods: Ce-doped CDs were prepared by microwave-assisted hydrothermal carbonization with cerium oxalate and glycine as precursors. The morphology was characterized by high power transmission electron microscopy. Fluorescence spectra were used to characterize its fluorescence properties. Near-infrared thermal imager was used to characterize the photothermal conversion efficiency. The photothermal killing effect of Ce-doped CDs was verified with 4T1 breast cancer cells in vitro. Results: Ce-doped CDs with uniform morphology, particle size of about 2.6 nm and good biocompatibility were successfully prepared, which had excellent fluorescence performance and photothermal conversion efficiency. As the concentration of Ce-doped CDs increased, 4T1 cell activity decreased under specific near-infrared light irradiation (808 nm), and normal cells had greater photothermal tolerance than tumor cells. Conclusion: Ce-doped CDs with fluorescence property and photothermal conversion efficiency were successfully prepared. The prepared Ce-doped CDs can effectively convert near-infrared light energy into heat energy, thus effectively kill tumor cells.

［Key words］cerium doped carbon quantum dots; photothermal therapy; carbon quantum dots; breast cancer cell; fluorescence; cell viability; photothermal ablation