Plasmon-Enhanced Peroxidase-like Activity of Nitrogen-Doped Graphdiyne Oxide Quantum Dots/Gold–Silver Nanocage Heterostructures for Antimicrobial Applications

Plasmon stimulation is an intriguing method to modulate the enzyme-mimic functions of nanomaterials, while utilization of plasmon excitation remains of low efficiency. Herein, by loading nitrogen-doped graphdiyne quantum dots (N-GDQDs) onto gold–silver nanocages (AuAg NCs), hollow cube-shaped N-GDQDs/AuAg NC heterostructures with strong local surface plasmon resonance (LSPR) response in the near-infrared (NIR) region are reported. This nanozyme can concurrently harvest LSPR-induced hot carriers and produce photothermal effects, resulting in a significantly enhanced peroxidase-like activity upon 808 nm irradiation. Both experimental data and theoretical calculations reveal that the remarkable catalytic performance of N-GDQDs/AuAg NCs results from the narrow band gap semiconductor characteristics of N-GDQDs, LSPR effect of AuAg NCs, and fast interfacial electron transfer dynamics. Moreover, this nanozyme is demonstrated to achieve >99.999% antibacterial efficiency against methicillin-resistant Staphylococcus aureus (MRSA), S. aureus, and Escherichia coli in 10 min in vitro and in vivo. This study not only sheds light on the mechanism of the nanozyme/photocatalysis coupling process but also provides a new avenue for rationally designing plasmonic metal/semiconductor-involved nanozymes for synergistic photothermal and photoenhanced nanozyme therapy.