Fabrication of Ag-incorporated TiO₂ film on TiNb substrate and evaluation on its antibacterial activity against E. coli

Abstract For the purpose of endowing TiNb alloy with antibacterial function, a two-step strategy was proposed to fabricate Ag-incorporated TiO2 film on TiNb substrate in this study. X-ray diffraction (XRD), Field-emission scanning electron microscopy (FESEM) and X-ray photoelectron microscopy (XPS) were used to characterize the crystal phases, morphologies and chemical compositions of the samples. The results showed that a layer of anatase TiO2 film with two kinds of morphologies was formed by hydrothermal treatment of TiNb alloy in NH4F-H2O2 solution. When the as-obtained TiNb-based TiO2 film was subjected to a further ultraviolet light irradiation in AgNO3 solution, metallic Ag granules with size range from 60 nm to 1.3 μm were uniformly deposited on the surface of TiO2 particles. Escherichia coli (E. coli) was selected as a model to estimate the bacteriostatic effect of the Ag-TiO2 film. The experimental result indicated that Ag-incorporated TiO2 exhibited excellent antibacterial activity against E. coli. It suggests that this two-step method for preparation of Ag-TiO2 composite film may provide an alternative strategy to reduce bacterial infection for Ti-implants in clinical application.