In Situ Formed Z-Scheme Graphdiyne Heterojunction Realizes NIR-Photocatalytic Oxygen Evolution and Selective Radiosensitization for Hypoxic Tumors

Photon radiotherapy is a common tool in the armory against tumors, but it is limited by hypoxia-related radioresistance of tumors and radiotoxicity to normal tissues. Here, we constructed a spatiotemporally controlled synergistic therapy platform based on the heterostructured CuO@Graphdiyne (CuO@GDY) nanocatalyst for simultaneously addressing the two key problems above in radiotherapy. First, the in situ formed Z-scheme CuO@GDY heterojunction performs highly efficient and controlled photocatalytic O2 evolution upon near-infrared (NIR) laser stimulation for tumor hypoxia alleviation. Subsequently, the CuO@GDY nanocatalyst with X-ray-stimulated Cu+ active sites can accelerate Fenton-like catalysis of center dot OH production by responding to endogenous H2O2 for the selective killing of tumor cells rather than normal cells. In this way, the sequential combination of NIR-triggered photocatalytic O2 production and X-ray-accelerated Fenton-like reaction can lead to a comprehensive radiosensitization. Overall, this synergism underscores a controllable and precise therapy modality for simultaneously unlocking the hypoxia and non-selectivity in radiotherapy.