BSA/LYZ-Mediated and Ultrasound-Assisted Synthesis of Silver Oxide Nanoparticles with Enhanced Bactericidal Performance

Introduction: Silver oxide nanoparticles (Ag 2 O NPs) have attracted considerable attention due to their excellent bactericidal performance; however, Ag 2 O NPs prepared by traditional chemical methods often suffer from issues such as large particle size and poor dispersibility, which limit their practical application. Methods: In this study, a protein-mediated, ultrasound-assisted synthesis method was employed to prepare Ag 2 O NPs. By regulating the concentrations of bovine serum albumin (BSA) and lysozyme (LYZ), as well as their addition order under an ultrasonic field, a series of Ag 2 O NPs were synthesized and subjected to physicochemical characterization and bactericidal performance evaluation. Furthermore, the bactericidal mechanism of Ag 2 O NPs was investigated based on Ag⁺ release, bacterial morphology and Live/Dead staining. Results: The results indicate that regulating the type and addition order of proteins could produce Ag 2 O NPs with different morphologies, among which those synthesized under ultrasonic conditions via BSA mediation exhibit the smallest hydrodynamic particle size (127.66 nm) and the highest absolute zeta potential (− 37.20 mV), and show the highest bactericidal efficiencies against Escherichia coli and Staphylococcus aureus , reaching approximately 95.97% and 98.69%, respectively. However, at higher LYZ concentrations (1g/L), the bactericidal efficiency of both ultrasonic-mediated and post-ultrasonic-mediated Ag 2 O NPs decreases significantly. The bactericidal activity of the Ag 2 O NPs is mainly associated with the synergistic effect of Ag⁺ release and bacterial membrane damage. Conclusion: This study provides a new strategy for the preparation of highly efficient bactericidal nanoparticles, and further analyzes their possible bactericidal mechanisms, providing useful insights for the design of novel antibacterial materials.