Spatiotemporally Synchronous Oxygen Self‐Supply and Reactive Oxygen Species Production on Z‐Scheme Heterostructures for Hypoxic Tumor Therapy
Yan Cheng, Xiangpeng Kong, Yun Chang, Yanlin Feng, Runxiao Zheng, Xiaqing Wu, Keqiang Xu, Xingfa Gao, Haiyuan Zhang
Abstract
Abstract Photodynamic therapy (PDT) efficacy has been severely limited by oxygen (O 2 ) deficiency in tumors and the electron–hole separation inefficiency in photosensitizers, especially the long‐range diffusion of O 2 toward photosensitizers during the PDT process. Herein, novel bismuth sulfide (Bi 2 S 3 )@bismuth (Bi) Z‐scheme heterostructured nanorods (NRs) are designed to realize the spatiotemporally synchronous O 2 self‐supply and production of reactive oxygen species for hypoxic tumor therapy. Both narrow‐bandgap Bi 2 S 3 and Bi components can be excited by a near‐infrared laser to generate abundant electrons and holes. The Z‐scheme heterostructure endows Bi 2 S 3 @Bi NRs with an efficient electron–hole separation ability and potent redox potentials, where the hole on the valence band of Bi 2 S 3 can react with water to supply O 2 for the electron on the conduction band of Bi to produce reactive oxygen species. The Bi 2 S 3 @Bi NRs overcome the major obstacles of conventional photosensitizers during the PDT process and exhibit a promising phototherapeutic effect, supplying a new strategy for hypoxic tumor elimination.