Near-infrared-II-driven Z-scheme heterojunction Polyglycolated MoS2/CoFe2O4 amplified edge potential for dual-mode imaging guided tumor synergistic therapy.

Targeting the peculiarities of tumor tissue microenvironment different from normal tissue, such as lower pH and overexpression of hydrogen peroxide is the key to effective treatment. In this study, acid-responsive Z-scheme heterojunctions polyglycolated MoS2/CoFe2O4 (MoS2 = molybdenum disulfide, CoFe2O4 = cobalt ferrite) was synthesized using a two-step hydrothermal method, designated as MSCO-PEG, guided by dual modes of photoacoustic imagine (PAI) and nuclear magnetic imaging (MRI). MSCO-PEG (PEG = polyethylene glycol) responded to the acidic environment of tumor tissues and overexpression of hydrogen peroxide to turn on multimodal synergistic treatment of tumor cells under near-infrared-II (NIR-II) illumination. In particular, MSCO-PEG amplified the oxidizing ability of edge valence band holes (h+) and the reducing ability of conduction band electrons (e-) under NIR-II illumination through a "step-like" charge transfer mechanism, promoting the conversion of H2O to oxygen (O2) and the generation of superoxide radicals (O2-). In addition, the outstanding light absorption and photothermal conversion ability of MSCO made it have excellent photodynamic therapy (PDT) and photothermal therapy (PTT) effects. Meanwhile, the abundant multivalent metals endowed MSCO-PEG with the ability to generate chemodynamic therapy (CDT). MSCO-PEG's ability to clear glutathione (GSH) promotes tumor oxidative stress, increases reactive oxygen species (ROS) production, and enhances the synergistic therapeutic effect. This work provides a promising approach to advancing the clinical application of nanomaterials for anticancer therapy targeting the tumor microenvironment.