Biomineralized Enzyme-Like Cobalt Sulfide Nanodots for Synergetic Phototherapy with Tumor Multimodal Imaging Navigation

Fabrication of nanotheranostic agents attracted a growing interest in accurate diagnosis and therapy of cancer by the sustainable biomineralization strategy. Herein, it is reported that biomineralized cobalt sulfide nanodots (Co9S8 NDs) with intrinsic peroxidase-like activity are potentially useful for synergetic phototherapy with tumor multimodal imaging navigation. The multifunctional Co9S8 NDs are first synthesized in aqueous phase via a simple biomineralization route. Detailed characterization reveals that the constructed peroxidase-like Co9S8 NDs not only possess strong paramagnetism with near-infrared absorption but also generate reactive oxygen species via photocatalytic reaction. As a result, the Co9S8 NDs reveal excellent performance for magnetic resonance and photoacoustic imaging of tumors, and outstanding tumor ablation efficiency owing to the near-infrared responsive photodynamic and photothermal effect. To our knowledge, ultrasmall Co9S8 NDs via aqueous phase synthesis have not been reported for multimodal theranostic applications so far.