Antibacterial effects of Ag-HAp thin films on alumina substrates

Abstract Ion beam assisted deposition (IBAD) has been successfully used to produce a dense ultra-adherent and pinhole-free hydroxyapatite (HAp) layer on alumina substrates. After deposition the HAp-coated alumina was immersed in 20 ppm and 100 ppm AgNO 3 solution to carry out the ion exchange between Ag + and Ca 2+ in HAp. An obvious antimicrobial effect against Escherichia coli , Pseudomonas aeruginosa , Staphylococcus aureus and Staphylococcus epidermidis was observed in the samples treated with 20 ppm AgNO 3 solution. In contrast to this, the untreated samples did not show any bactericidal effect. Scanning electron microscopy (SEM) studies showed that Ag-rich phases were homogeneously distributed on the surface. X-ray diffraction (XRD) demonstrated that the surface structure in the samples without Ag was HAp, whereas with Ag it is HAp and AgCaP. The minimum inhibitory concentration of AgNO 3 was measured to be 1.302 μg/ml. The release of Ag + ions from the Ag-HAp films in simulated body fluid (SBF) solution was determined by atomic absorption spectroscopy.