Revealing the antibacterial mechanism of copper surfaces with controllable microstructures

Although extensive experiments confirm the ability of copper for biofouling protection, its further utilization is still limited in virtue of unclear relationship between the surface topography and antibacterial performance. In this study, the hydrophobic copper surfaces with different morphologies, including nanowire, nanowire/microflower, and nanosheet/microflower hierarchical structures, were prepared through the one-step chemically etched method and in-situ self-assembly strategy. According to the four-time cyclic antibacterial assays for E. coli and B. subtilis , the copper with nanowire structure displayed a better antibacterial performance than others. Bacteriostasis rate of nanowire structure copper was over 90% in the first cycle, and reached 100% in the final test. In addition, the morphologies of copper surfaces after antibacterial test suggested that nanowire and microflower structures could significantly suppress the adhesion of bacteria. Besides, nanowire structure exerted an outstanding function in inhibiting bacterial adhesion under a lower concentration of inorganic salt.