Morphology-Tunable CeO2-Shelled Gold Nanospheres for Synergistic Photothermal and Dual Enzyme-Like Antibacterial Performance

Multifunctional nanomaterials are promising for effective antibacterial applications, yet single-component systems remain limited by insufficient catalytic activity and poor biocompatibility. Herein, core−shell Au@CeO2 nanocomposites with porous (Au@P−CeO2) and sheet-like (Au@S−CeO2) morphologies were constructed to achieve photothermal−catalytic synergistic antibacterial performance. The Au core enables efficient photothermal conversion, while the CeO2 shell provides dual enzyme-mimetic activitiesperoxidase-like for •OH generation and superoxide dismutase-like for •O2− scavenging. Au@S−CeO2 exhibits superior POD activity and completely eradicates Staphylococcus aureus (with 0.001 wt % H2O2) and E. coli (with 0.002 wt % H2O2) at only 3 μg mL−1 (based on Ce) in the dark; 660 nm laser irradiation further reduces the bactericidal threshold to 2 μg mL−1 via photothermal−catalytic synergy. Both nanocomposites maintain excellent hemocompatibility and cytocompatibility (cell viability >95%) at working doses. This work offers a facile strategy for integrating photothermal and dual enzyme-mimetic functions into a single nanoplatform for multifunctional antibacterial applications.