Ultra small gold nanoclusters supported on two-dimensional bismuth selenium nanosheets for synergistic photothermal and photodynamic tumor therapy.

Two-dimensional (2D) bismuth selenium (Bi 2 Se 3 ) nanosheets have exceptional surface area and superior surface modification capabilities, facilitating the effective loading of nanoprobes, metal particles, and other substances. Additionally, thiolated ultrasmall gold nanoclusters (Au NCs), distinguished by their high photoluminescent activity and modulatable surface charges, enable efficient loading onto the 2D Bi 2 Se 3 surfaces. In this study, we successfully prepared Bi 2 Se 3 nanosheets by sonication-assisted liquid phase exfoliation and loaded Au clusters on their surface through an amide bond reaction. The loading of Au NCs significantly augments the photothermal and photocatalytic capabilities of Bi 2 Se 3 nanosheets and exhibits obvious anti-cancer therapeutic effects through in vitro and in vivo experiments. In summary, the as-prepared AuNC@Bi 2 Se 3 nanocomposites showed combined near-infrared light-initiated photothermal/photodynamic therapy (PTT/PDT) against tumors, demonstrating their potential as novel theranostic agents for biomedical applications.