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.