Synergistic antibacterial activity and mechanism of silver nanoplates and ozone against multidrug-resistant Staphylococcus Aureus

Two-dimensional Ag nanoplates exhibit robust facet-mediated catalytic activity for ozone adsorption and decomposition, accompanied by asymmetric particle dissolution, ROS generation, and concomitant Ag + release. • The synergistic antibacterial effects of Ag nanoparticles and ozone confer superior efficacy, effectively overcoming the defense mechanisms of drug-resistant bacteria and eradicating multidrug-resistant S. aureus strains. The overuse of antibiotics drives the emergence and dissemination of bacterial resistance, thereby escalating global risks associated with exposure to multidrug-resistant (MDR) bacteria, a challenge demanding urgent worldwide attention. Recent studies show that certain bacteria can even develop resistance phenotypes against engineered antibacterial nanomaterials, including silver (Ag)-based nanomaterials. However, effective strategies to counteract such resistance remain elusive. Herein, we propose a simple, low-cost synergistic antibacterial strategy that enhances the antimicrobial efficacy of Ag nanoparticles via ozone, a green, environmentally benign disinfectant widely deployed in water and surface treatment. Mechanistically, Ag nanoparticles exert morphology- and crystal facet-dependent antibacterial effects through three interrelated pathways: catalytic decomposition of ozone, generation of reactive oxygen species (ROS), and release of Ag + ions. Compared with the most used spherical Ag nanoparticles, two-dimensional Ag nanoplates (Ag NPLs) demonstrate significantly superior eradication efficiency against MDR Staphylococcus aureus strains in both in vitro and in vivo settings. This enhanced activity arises from the preferential {100} and {110} facet-mediated adsorption and decomposition of ozone, as well as more favorable interactions at the nano–cell interface. Overall, this ozone-assisted synergistic antibacterial approach presents a promising alternative for combating MDR pathogens, highlighting its substantial potential to mitigate environmental contamination and reduce infection risks posed by resistant microbes.