An All-in-One Organic Semiconductor for Targeted Photoxidation Catalysis in Hypoxic Tumor.

Tumor hypoxia severely limits the therapeutic effects of photodynamic therapy (PDT). Although many methods for oxygen generation exist, substantial safety concerns, spatiotenporal uncontrollability, limited efficacy and complicated procedures have compromised their practical application. Here, we demonstrate the feasibility of a biocompatiable all-in-one organic semiconductor to provide a photoxidation catalysis mechanism of action to combat these challenges. A one-step and facile method is developed to produce gram-level C5N2 nanoparticles (NPs)-based organic semiconductor. Under 650 nm laser irradiation, the semiconductor split water to generate O2 and simultaneously produced singlet oxygen (1O2), revealing that the photocatalyst for O2 evolution and the photosensitizer (PS) for 1O2 generation could be synchronously achieved in one organic semiconductor. Furthermore, the inherent nucleus targeting capacity endows it with direct and efficient DNA photocleavage. These findings pave the way for developing organic semiconductor-based cancer therapeutic agents.