One-pot assembly of gold nanoparticles in different dimensional MOFs with peroxidase-like activity for enhanced bacterial eradication

Bacterially infected wounds are a hidden danger to human health, and the elimination of invasive wound bacteria is critical for proper wound healing. Nanozymes with peroxidase (POD)-like and catalase (CAT)-like activities serve as promising antimicrobial agents since they avoid the damage caused by high concentrations of hydrogen peroxide (H2O2) while providing sufficient oxygen (O2). Herein, we report hybrid composites of gold nanoparticles (AuNPs) assembled on two-dimensional or three-dimensional (2D/3D) Zn-based metal organic frameworks (Zn-MOFs) via free amino groups. Specifically, the formed 3D Zn-MOF@Au, which combines the advantages of AuNPs and stabilized 3D MOFs, exhibits more significant POD-like activity in terms of decomposing H2O2 into toxic hydroxyl radicals than 2D Zn-MOF@Au while being able to supply sufficient O2. We performed systematic antimicrobial tests against bacteria using this composite nanomaterial with different dimensions, and the results showed that the 3D Zn-MOF@Au composite had better antibacterial effects against gram-positive (methicillin-resistant Staphylococcus aureus, MRSA) and gram-negative (Escherichia coli, E. coli) bacteria with the addition of a low dose of H2O2. Animal experiments showed that this hybrid composite effectively accelerated bacteria-infected wound healing with excellent biocompatibility. This study demonstrated the great promise of metal nanoparticles modified different dimensional MOFs for antimicrobial therapy applications.