Rapid bacteria capturing and killing by AgNPs/N-CD@ZnO hybrids strengthened photo-responsive xerogel for rapid healing of bacteria-infected wounds

Rapid bacteria killing and tissue repair are critical for the fast healing of bacteria-infected wounds, especially under poor sanitation without antibiotics. Herein, we prepared a novel xerogel constructed by thioether as a main chain and embedded by Ag nanoparticles (NPs) and ZnO NPs decorated by N-doped carbon dots (NCD@ZnO). This hybrid xerogel not only has good mechanical properties without swelling but also has the ability to capture bacteria rapidly by the disulfide group through electrostatic interaction. Under 808 nm near-infrared (NIR) light irradiation for 15 min, this hybrid xerogel killed 99.9% Escherichia coli and 99.85% Staphylococcus aureus by the synergistic action of released Ag+ and reactive oxygen species (ROS) produced by N-CD@ZnO using up-conversion technology (N-CD reduces the biotoxicity of ZnO and changes its photocatalytic response region from the 368 nm ultraviolet (UV) region to the 808 nm NIR region). In addition, the biotoxicity of Ag+ is limited by the Ag-S covalent bond, which ensures good biocompatibility for the xerogel. Finally, in wound repair experiments in vivo, this xerogel is able to completely repair the wound within 10 days. This work will open up a new avenue for xerogel antibacterial materials.