Green and rapid synthesis of cysteine-directed novel AgCu nanocluster hydrogel with good antibacterial activity

Abstract Because of the problem of bacterial resistance, inorganic antibacterial materials represented by metallic nanomaterials have attracted attention for their antimicrobial properties. However, their antibacterial efficiency and safety need to be improved, and the cost of preparation needs to be reduced. Here a novel and highly stable cysteine-directed silver-copper composite nanoclusters hydrogel (AgCu NCs hydrogel) was prepared by employing a simple and green UV photoreduction one-pot method. The optical properties, structure and synthesis principle of AgCu NCs hydrogel were characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), and X-Ray photoelectron spectroscopy (XPS), respectively. The antibacterial activities of AgCu NCs hydrogel against Esherichia coli (E.coli) and Staphylococcus aureus (S.aureus) were evaluated using zones of inhibition, minimum inhibitory concentrations (MIC), minimum bactericidal concentration (MBC), and growth curves. The AgCu NCs hydrogel shows highly synergistic antibacterial performance toward both E.coli and S.aureus with the MIC of 0.781 μg/mL, 3.125 μg/mL and MBC of 12.5 μg/mL, 100 μg/mL, respectively. In addition, due to the good biocompatibilities, the AgCu NCs hydrogel has a good therapeutic effect on burn wounds. It will eventually become a new, low-cost, and highly effective antibacterial medical dressing.