A new antibacterial Ca/P/Al containing coating

The antibacterial capabilities of the microarc oxidation coating have attracted considerable attention in biomaterial and marine fouling. Herein, a facile and low-cost Ca/P/Al containing microarc oxidation coating without any bactericides is proved to be notably antibacterial. The viability of Escherichia coll. and Staphylococcus aureus is inhibited by Ca/P/Al coating at the most extent based on the results of spread plate method and fluorescence staining. The reasons for antibacterial activity are linked to the extracellular and intracellular reactive oxygen species (ROS). The dissolved matters from the amorphous surface layer of the Ca/P/Al coating trigger the formation of the extracellular ROS, which destroy the bacterial cell wall and membrane and lead to the cytoplasmic leakage. Meanwhile, the coating stimulates the generation of the intracellular ROS, these ROS interact with the cytoplasm and impair the bacterial metabolism. The cooperative effects of the extracellular and intracellular ROS eventually result in the bacterial death.