Multifunctional Ag₂S/g-C₃N₄ Nanoparticles for Photodynamic and Photothermal Cancer Therapy under Near-Infrared Excitation

Photothermal therapy (PTT) agents possess the capability to absorb light and transform it into heat, providing a promising approach for inhibiting and eradicating tumor cells. Therefore, there is a significant interest in developing novel PTT agents with superior biocompatibility and photothermal conversion efficiency. Herein, Ag₂S/g-C₃N₄ nanoparticles (NPs) with exceptional near-infrared absorption performance were successfully synthesized using a hydrothermal method. The photothermal conversion efficiency of Ag₂S/g-C₃N₄ NPs reached 31.28% under 808 nm laser irradiation, surpassing that of most reported PTT agents. The simultaneous application of an 808 nm laser resulted in a significant augmentation of reactive oxygen species (ROS) generation, including ·O₂^- and ·OH, which, in turn, triggered apoptosis and the death of tumor cells via photodynamic therapy (PDT). The efficacy of tumor elimination was confirmed through cellular and animal experiments, demonstrating the synergistic effectiveness of PTT and PDT. Importantly, no tumor regrowth was observed for 30 days after synergistic treatment. These results highlight the potential of combining photodynamic and photothermal therapies in nanomaterials for effective tumor therapy, offering a novel approach to tumor catalytic-photothermal therapy utilizing nanomaterials.