NIR enhanced peroxidase-like activity of Au@CeO2 hybrid nanozyme by plasmon-induced hot electrons and photothermal effect for bacteria killing

Abstract The antibacterial application of nanozyme relies on high catalytic efficiency and advanced functions. Plasmon stimulation represents an appealing way to modulate the enzyme-like function, but the utilization efficiency of plasmon excitation remained relatively low. Herein, by selective deposition of a ceria nanozyme on the ends of Au nanorods, we reported a dumbbell-shaped Au@CeO2 hybrid nanozyme with strong surface plasmon resonance (SPR) response in NIR range. This spatially separated structure can simultaneously harvest the plasmon-induced hot carriers and thermal effect, and results in significantly enhanced peroxidase-like activity of Au@CeO2 upon 808 nm irradiation. By using ultrafast transient absorption and in situ irradiation XPS technique, the hot electrons transfer behavior from Au to CeO2 and leading to the change of Ce3+/Ce4+ ratio are disclosed as the main contribution to the activity enhancement. Benefiting from enhanced peroxidase-like activity, Au@CeO2 exhibits efficient broad-spectrum antibacterial activity under NIR irradiation. These results indicate a spatio-temporal way to optimize enzyme-like activity through efficient use of plasmon excitation will be value for improving antibacterial efficacy.