The antibacterial W-containing microarc oxidation coating on Ti6Al4V

The antibacterial properties of the microarc oxidation coating have gained wide attentions, and W-containing surface has been verified to be notably bactericidal. Herein, in this work, doping Na 2 WO 4 into the electrolyte to prepare the antibacterial W-containing microarc oxidation coating is proposed for the first time. No obvious crystal phase related to hexavalent W exists in the coating, and sodium tungstate may transform into a trace amount of tungsten oxides and amorphous substances. The sodium tungstate plays a crucial role in the antibacterial capability of the coating, the W-containing coating exhibits conspicuous bactericidal performance against both planktonic and adherent Escherichia coli and Staphylococcus aureus . The antibacterial mechanism of the W-containing coating is first revealed to be linked to the extracellular and intracellular reactive oxygen species (ROS). The W-containing dissolved matters spontaneously trigger the formation of the extracellular ROS, which directly destroy the bacterial cytoderm and cytomembrane. Meanwhile, the nanoscale W-containing dissolved matters penetrate the cell wall, and stimulate the generation of intracellular ROS which interact with the cytoplasmic components. Ultimately, the bacteria die from the cooperative effects of the extracellular and intracellular ROS.