Synthesis of water-soluble Cu/PAA composite flowers and their antibacterial activities

Water-soluble copper/polyacrylic acid (Cu/PAA) composites were synthesized by a facile solution-phase reduction route. The Cu/PAA composites presented flower-like architecture, consisting of several intercrossing sheets, and reaction conditions had an important effect on their morphologies. Their antibacterial activity towards the bacterial strains such as Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) were evaluated by the minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC), cup diffusion method and optical density (OD600). Results indicated that Cu/PAA flower is selective in its antibacterial action. It displays more effective antibacterial activity against B. subtilis than other three stains, and better bactericidal activity against S. aureus, E. coli and P. aeruginosa than B. subtilis. There is no bactericidal ability against B. subtilis in the tested concentration range, which indicates that B. subtilis may be a copper-tolerant bacterium.