Structure, antibacterial property and cytocompatibility of sputter deposited MoO–Ag films

Abstract

MoO–Ag films with silver content up to 18.6 at.% along with MoO films were prepared by magnetron sputtering. The film color reveals oxidation of Mo element in both groups of films. XRD analysis shows bcc Mo phase, fcc Mo(O) solid solution and fcc silver phase (only for MoO–Ag films), and XPS analysis reveals oxidation of Mo element. SEM displays the increased density of silver nanoparticles at film surface with silver content of the MoO–Ag films. With the addition of oxygen the conductivity of MoO films is decreased to above 2 kΩ. Both groups of samples are hydrophilic, with the contact angles of 51.2–83.9°. The electrochemical test suggests microgalvanic coupling in the composite MoO–Ag film (11.8 at% Ag). The composite film sample also has the higher Mo ion releasing rate in water. Both groups of films exhibit good antibacterial activity against E. coli (antibacterial ratio up to 100%) contributed by the released Mo and Ag ions. The extracts of MoO–Ag films with silver content up to 11.8 at% are well compatible with MC3T3-E1 cells. With the biologically advantageous Mo element and acceptable released Ag ion concentration, the sputter deposited MoO–Ag films would have high potential in biomedical applications.