Solvent-Assisted Self-Assembly of a Metal–Organic Framework Based Biocatalyst for Cascade Reaction Driven Photodynamic Therapy

Biocatalytic reactions in living cells involve complex transformations in the spatially confined microenvironments. Inspired by biological transformation processes, we demonstrate effective biocatalytic cascade driven photodynamic therapy in tumor-bearing mice by the integration of an artificial enzyme (ultrasmall Au nanoparticles) with upconversion nanoparticles (NaYF4@NaYb0.92F4:Er0.08@NaYF4)zirconium/iron porphyrin metal–organic framework core–shell nanoparticles (UMOF NPs) which act as biocatalysts and nanoreactors. The construction of core–shell UMOF NPs are realized by using a unique "solvent-assisted self-assembly" method. The integration of ultrasmall AuNPs on the UMOFs matrix leads to glucose depletion, providing Au-mediated cancer therapy via glucose oxidase like catalytic activity. Meanwhile, the UMOF matrix acts as a near-infrared (NIR) light photon-activated singlet oxygen generator through a continuous supply of oxygen via hydrogen peroxide decomposition upon irradiation. Such kinds of biocatalysts offer exciting opportunities for biomedical, catalytical ,and energy applications.