Fabrication of nano CuAl 2 O 4 spinel for copper stabilization and antibacterial application.

With widely reported antibacterial potential, the copper-containing nanoparticles have become attractive antibacterial agents to prohibit the undesirable bacterial adhesion and growth. However, after applying the copper-containing agents in the environment, the potential leaching and bioaccumulation of copper ions may cause severe environmental contamination and irreversible health problems. Therefore, the nano CuAl2 O4 spinel was fabricated as a novel copper-stabilized antibacterial agent with much minimized copper leachability. Results show the successful fabrication of nano CuAl2 O4 spinel as well-shaped polyhedral particles with maximum length of ˜100 nm and width of ˜50 nm. The optimal parameters for the synthesis of CuAl2 O4 include pH value of 11.0, sintering temperature of 1000 °C, dwelling time of 3 h, and the heating rate of 5 °C/min. The leaching test also confirmed the superiority of the nano CuAl2 O4 in copper stabilization. The beneficial antibacterial activity of the nano CuAl2 O4 was further testified by an obvious decrease in the amount of Escherichia coli in a medium with addition of the CuAl2 O4 spinel. Besides the growth mechanisms of the nano-particles, this work has also innovatively demonstrated a strategy to replace the traditional antibacterial agents by a novel, long-lasting nano CuAl2 O4 with little copper leachability.