NIR-II sensitive Co9S8/S-CDs@PEG nanocomposites with enhanced multi-enzyme mediated phototherapy

Here, Co 9 S 8 / [email protected] ( [email protected] ) nanocomposites are synthesized by a two-step hydrothermal process. Firstly, sulfur-doped carbon dots (S-CDs) are prepared by using 3-mercaptopropionic acid as a precursor. A region with denser –SH group is regarded as nucleation site on S-CDs for the growth of Co 9 S 8 to induce heterostructure. As-synthesized [email protected] possess great harvest in NIR region and hyperthermia (51.5%, 1064 nm) for photothermal (PTT). Besides, hyperthermia can elevate the thermal energy of nanocomposite to assist low-energy NIR-II irradiation (1064 nm, 1.16 eV), realizing the excitation of Co 9 S 8 (1.46 eV) and reactive oxygen species (ROS) generation for photodynamic therapy (PDT). What's more, [email protected] exhibits GOx-like activity that could consume glucose to elevate H 2 O 2 level and inhibit intracellular energy supply. In addition, they also show mimic peroxidase (POD) and catalase (CAT) characterization, and the tandem multi-nanozye activities endue the enhanced chemotherapy (CDT) and PDT. [email protected] reveals the greater ROS generation and nanozyme activity compared with pure Co 9 S 8 @PEG, attributing to the efficient charge separation in heterostructure. The novel biodegradation of [email protected] makes the elimination via feces and urine within 2 weeks. That is associated with PTT/PDT/CDT/starvation therapy to activate immune response for anticancer.