Synthesis, characterization and investigation on synergistic antibacterial activity and cytotoxicity in vitro of Ag-CuSn nanocolloids

Ag or Cu NPs are typical antibacterial agents, and the pursuit of the strong efficacy under the low dosage makes them towards bimetallic or trimetallic exploration. In this study, Ag-(CuSn) nanocolloids (NCs) based on Cu, Sn and next Ag have been prepared by two steps of the chemical reduction. Phases, morphologies, structure relationships were characterized, the elements releasing behaviors in deionized water, the antibacterial performance over S. aureus, E. coli and C. albicans and the toxicity on L929 cells were also investigated. Results showed Cu, Sn were first reduced into Cu6.26Sn5 alloy, Ag was further deposited on CuSn nanoparticles to form Ag-(CuSn) NCs, the NCs showed a sphere-like morphology with average size less than 30 nm, the structure changed from Ag decorated CuSn to Ag coated one as Ag amounts increased. Ag-(CuSn) NCs displayed lower MIC/MBC than those of Ag or CuSn NPs under the synergistic effect. The suppression on Cu and Ag releasing made Ag0.2-(CuSn) NCs and Ag0.8-(CuSn) NCs perform nontoxic, both good antibacterial ability and biosafety to cells offered them a potential clinical application.