Near-field coupling resonance enhancement with AuNiO Heterostructure nanosheets for high-performance photodynamic/photothermal Hybrid antibacterial & imaging tracking.

Bacterial infection has always been a serious public health problem worldwide. Real-time microbial monitoring in the trauma resuscitation unit is crucial for infection control and plays an essential role in all aspects of wound treatment clinical practice, such as identification and evaluation of wound infection, diagnosis of wound infection, and topical antimicrobial treatment. Herein, gold-loaded nickel oxide nanosheets (Au-NiO NSs) prepared by hydrothermal and laser-assisted synthesis methods are used as fluorescent nanoprobes to rapidly detect and target bacteria at an early stage, and then achieve combined PTT and PDT to inactivate bacteria under sunlight. Optical detection, electronic structure and plasma local field analysis show that there is charge transfer between Au10-O-NiO through the O-Au-O bond, and effectively improves the plasmon effect through resonant energy transfer, achieving higher photothermal conversion efficiency. The detection limits of Staphylococcus aureus and Pseudomonas aeruginosa are as low as 145.6 and 157.7 cfu/mL, respectively, and the sterilization rates are both above 99%. In addition, Au-NiO NSs have low cytotoxicity, and the nanocomposite dressing prepared by combining Au-NiO NSs with hydrogels demonstrates the ability to monitor and kill pathogens in situ in the treatment of skin wounds. The platform integrates the targeting, imaging and inactivation capabilities of bacteria, showing great application potential in the field of bacterial diagnosis and treatment.