Carbon quantum dots/Bi <sub>4</sub> O <sub>5</sub> Br <sub>2</sub> photocatalyst with enhanced photodynamic therapy: killing of lung cancer (A549) cells in vitro
Bing He, Haiyan Jin, Yawen Wang, Caimei Fan, Yunfang Wang, Xiaochao Zhang, Jianxin Liu, Rui Li, Jue-Wen Liu, Rui Li, Jue-Wen Liu
Abstract
Abstract Inorganic photocatalysts have been regarded as a promising candidate in the domain of tumor photodynamic therapy (PDT) due to their inspirational photocatalytic activity. In this study, a Bi 4 O 5 Br 2 photocatalyst was synthesized and it exhibited effective photo‐killing activity of A549 cells (a human lung carcinoma epithelial cell line) in vitro. On this basis, we modified Bi 4 O 5 Br 2 with carbon quantum dots (CQDs) via a hydrolysis method at room temperature, which resulted in an improved photo‐killing effect of Bi 4 O 5 Br 2 to A549 cells. The samples and the interaction between samples and cells were fully characterized. It has been found that the loading of CQDs on Bi 4 O 5 Br 2 can reduce the hydration ratio, increase the cellular uptake and improve the photogenerated reactive oxygen species (ROS) as compared with pristine Bi 4 O 5 Br 2 . Electron spin resonance (ESR) analysis and radical‐trapping experiments manifested that the ROS contributed to PDT may be ·O 2 − and ·OH. This study may provide a useful strategy to ameliorate the penetrability, cell compatibility and PDT effect upon cancer cells of other inorganic photocatalysts.