Phosphorescence Enzyme-Mimics for Time-Resolved Sensitive Diagnostics and Environment-Adaptive Specific Catalytic Therapeutics

Enzyme mimics (EMs) with intrinsic catalysis activity have attracted enormous interest in biomedicine. However, there is a lack of environmentally adaptive EMs for sensitive diagnosis and specific catalytic therapeutics in simultaneous manners. Herein, the coordination modulation strategy is designed to synthesize silicon-based phosphorescence enzyme-mimics (SiPEMs). Specifically, the atomic-level engineered Co-N-4 structure in SiPEMs enables the environment-adaptive peroxidase, oxidase, and catalase-like activities. More intriguingly, the internal Si-O networks are able to stabilize the triplet state, exhibiting long-lived phosphorescence with lifetime of 124.5 ms, suitable for millisecond-range time-resolved imaging of tumor cells and tissue in mice (with high signal-to-background ratio values of similar to 60.2 for in vitro and similar to 611 for in vivo). Meanwhile, the SiPEMs act as an oxidative stress amplifier, allowing the production of OH via cascade reactions triggered by the tumor microenvironment (similar to 136-fold enhancement in peroxidase catalytic efficiency); while the enzyme-mimics can scavenge the accumulation of reactive oxygen species to alleviate the oxidative damage in normal cells, they are therefore suitable for environment-adaptive catalytic treatment of cancer in specific manners. We innovate a systematic strategy to develop high-performance enzymemics, constructing a promising breakthrough for replacing traditional enzymes in cancer treatment applications.