Missing‐Linker‐Confined Single‐Atomic Pt Nanozymes for Enzymatic Theranostics of Tumor

Conventional nanozymes often possess low active site density. Pursuing effective strategies for constructing highly active single-atomic nanosystems with maximum atom utilization efficiency is exceptionally attractive. Herein, we develop a facile “missing-linker-confined coordination” strategy to fabricate two self-assembled nanozymes, i.e., conventional nanozyme (NE) and single-atomic nanozyme (SAE), which respectively consist of Pt nanoparticles and single Pt atoms as active catalytic sites anchored in metal-organic frameworks with encapsulated photosensitizers for catalase-mimicking enhanced photodynamic therapy. Compared to Pt nanoparticle-based conventional nanozyme, Pt single-atomic nanozyme shows enhanced catalase-mimicking activity in generating oxygen for overcoming tumor hypoxia, thus presenting more efficient reactive oxygen species generation and high tumor inhibition rate.