Efficient elimination of multidrug-resistant bacteria using copper sulfide nanozymes anchored to graphene oxide nanosheets

Antibacterial nanomaterials have attracted growing interest for bacterial infection therapy. However, most nanomaterials eliminate bacteria either physically or chemically, which hampers their efficacy when dealing with multidrug-resistant bacteria. To overcome this, we integrated copper sulfide (CuS) nanoparticles with active graphene oxide nanosheets (GO NSs) to synthesize a superior nanocomposite (CuS/GO NC) that acts both physically and chemically on the bacteria. CuS/GO NC was produced using a facile hydrothermal method, whereby the CuS nanoparticles grew and were uniformly dispersed on the GO NSs in situ. We found that the CuS/GO NC possesses a unique needle-like morphology that physically damages the bacterial cell membrane. CuS/GO NC also exhibits high oxidase- and peroxidase-like activity, ensuring efficient generation of the reactive oxygen species •OH from H₂O₂, which kills bacteria chemically. These features endow the CuS/GO NC with excellent antibacterial capabilities to kill multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) with only a single dose. Additionally, it was found that the CuS/GO NC accelerated the healing of infected wounds in vivo owing to its good biocompatibility as well as facilitation of cell migration and collagen secretion. This study provides a new strategy to combine the physical and chemical antibacterial modes of nanomaterials to develop more effective therapies to combat multidrug-resistant bacterial infections.