Multifunctional Hollow Bimetallic Sulfide Nanozyme Enables Imaging-Guided Synergistic Ferrotherapy for Tumor Treatment

The design of nanozymes with controlled properties and well-defined mechanisms holds significant promise for advancing next-generation functional biomaterials for tumor theranostics. Here, we develop a metal-organic framework (MOF)-derived bimetallic sulfide nanozyme, FCS, for ferrotherapy via combined photothermal and catalytic therapies. FCS is synthesized by vulcanizing the zeolitic imidazolate framework-67 (ZIF-67) into cobalt sulfide (Co3S4, CS), followed by ferrous cation exchange, resulting in enhanced near-infrared II photothermal conversion and superior Fenton-like catalytic activity. Theoretical calculations attribute these enhancements to Fe doping, which narrows the band gap, promotes electron transfer to H2O2, and lowers the energy barrier for active oxygen species generation. FCS effectively induces ferroptosis through lipid peroxidation, while supporting T2-weighted magnetic resonance imaging. This study presents a robust strategy for MOF transformation into multifunctional tumor theranostic agents, highlighting the role of metal ion doping in optimizing nanozyme performance.