Nano-flower-stick S-scheme Au/MoS2/Bi2S3 heterojunction with multiple enzyme-like activity for efficient tumor photothermal and photodynamic combination therapy

Nano-catalytic therapy mediated by reactive oxygen species (ROS) is a highly promising tumor treatment strategy. However, the unique physiological and biochemical characteristics of tumor microenvironment, such as hypoxia and overexpression of antioxidants and glutathione, limit the production of ROS and their oxidation capacity within the tumor. In this study, an S-scheme heterojunction (Au/MoS2/Bi2S3) with multiple enzyme activities was constructed to achieve significant anti-tumor effects through photothermal/photodynamic combination therapy (PTT/PDT). Under near infra-red irradiation, Au/MoS2/Bi2S3 heterojunction not only provided high fever for PTT but also generated singlet oxygen for PDT. In addition, the Au/MoS2/Bi2S3 heterojunction also could generate H2O2 in-situ (Glucose oxidase-like activity), meanwhile simultaneously complete the decomposition of endogenous H2O2 (Peroxidase-like and Catalase-like activity) and depletion of glutathione (Glutathione-peroxidase-like activity) through the conversion between Mo4+ and Mo6+, further enhancing the generation of ROS. In vitro and in vivo studies demonstrated that the photoactivated Au/MoS2/Bi2S3 heterojunction with multiple enzyme activities could completely eliminate tumors without recurrence, meanwhile this heterojunction also exhibited the high biological safety. This study provided a new perspective for tumor therapy based on nano-catalytic method.