Photocatalytic inactivation effect of gold-doped TiO 2 (Au/ TiO 2) nanocomposites on human colon carcinoma LoVo cells

Abstract

The photocatalytic inactivation effecting of gold-doped TiO 2 (Au/ TiO 2) nanocomposites on human colon carcinoma LoVo cells was investigated for the first time. The Au/ TiO 2 samples containing different amounts of Au (1-4 wt) were prepared by deposition-precipitation (DP) method. These synthesized Au/ TiO 2 nanocomposites were characterized by transmission electron microscopy (TEM) and inductively coupled plasma atomic emission spectroscopy. It was found that the photocatalytic inactivation effect of TiO 2 nanoparticles on LoVo cancer cells could be greatly improved by the surface modification of Au nanoparticles. Furthermore, the loading amount of Au on the surface of TiO 2 nanoparticles affects the photocatalytic inactivation efficiency strongly, and it was found that the most efficient nanocomposites were TiO 2 nanoparticles doped with 2 wt Au. When 50 μg/mL 2 wt Au/ TiO2 nanocomposites were used, all of the LoVo cancer cells were killed under the irradiation of UV light ( λ max = 365 nm, Intensity = 1.8 mW/ cm 2) within 100 minutes. But for 50 μg/mL TiO2 nanoparticles, only 40 cancer cells were killed under the same condition.