Plasmon-activated nanozymes with enhanced catalytic activity by near-infrared light irradiation

Nanozymes have attracted extensive attention due to their great potential as alternatives to natural enzymes. Optical control as an external stimulus has become the most attractive method because of its high spatial and temporal resolution. Under the action of excitation light, free electrons on the surface of gold nanorods (GNRs) will collectively oscillate, which is called localized surface plasmon resonance (LSPR). This unique LSPR effect is promising in the application of plasmon-accelerated enzyme-like catalytic reactions. Pt-tipped gold nanorod-based nanozymes (Pt-GNRs) were synthesized by the modification of Pt nanoclusters onto the tips of GNRs. The as-prepared Pt-GNRs exhibited excellent enzyme-like catalytic activity toward hydrogen peroxide. Furthermore, it was found that the enzyme-like catalytic activity of Pt-GNRs could be notably enhanced using near-infrared (NIR) light irradiation, because of the photothermal effect and hot electron effect produced by the LSPR of GNRs. Finally, the catalytic activity and cytotoxicity of Pt-GNRs were evaluated in 4T1 cells, which further demonstrated that the Pt-GNR-based nanozymes possess great potential in cancer treatment.