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 <i>T₂</i>-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.