In situ growth of self-organized Cu-containing nano-tubes and nano-pores on Ti90 − xCu10Alx (x = 0, 45) alloys by one-pot anodization and evaluation of their antimicrobial activity and cytotoxicity

In this paper, we report on the formation of in situ self-organized Cu-containing nanotube and nanopore oxide structures by one-pot anodizing of Ti- and TiAl-related alloys in NH4F containing ethylene glycol electrolytes. The microstructure of the as-doped bi/ternary alloys and resultant nanotubular or nanoporous oxide layers was characterized using X-ray diffraction (XRD), field-emission-scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). It reveals that the Ti–10Cu alloy is mainly composed of Ti3Cu, TiCu and Ti phases while the TiAl–10Cu comprises TiAl, TiCu, Ti and Al phases. After anodization, the Cu containing self-aligned nanotubular and nanoporous structure can be successfully formed on Ti–10Cu and TiAl–10Cu, respectively. XPS result indicates that the residual Cu embedded in the form of CuO on the as-formed oxide nanostructures. The antibacterial tests (spread plate counting and fluorescence staining) show that, all antibacterial rates for Escherichia coli and Staphylococcus aureus can reach to above 99% on surface of anodized TiCu–O and TiAlCu–O. Moreover, both of the as-anodized TiCu–O and TiAlCu–O exhibit no cytotoxicity to the growth of osteoblast cells. These in situ self-organized Cu-containing nano-tubular and nano-pore oxide structures integrating with favorable antimicrobial activity and excellent biological property will find potential applications in fields of antimicrobial materials, biomedical or implanting devices, etc.