Photocatalytic Inactivation Effect of Gold-DopedTiO2(Au/TiO2) Nanocomposites on Human Colon Carcinoma LoVo Cells

The photocatalytic inactivation effecting of gold-doped TiO2 (Au/TiO2) nanocomposites on human colon carcinoma LoVo cells was investigated for the first time. The Au/TiO2 samples containing different amounts of Au (1–4 wt%) were prepared by deposition-precipitation (DP) method. These synthesized Au/TiO2 nanocomposites were characterized by transmission electron microscopy (TEM) and inductively coupled plasma atomic emission spectroscopy. It was found that the photocatalytic inactivation effect of TiO2 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 TiO2 nanoparticles affects the photocatalytic inactivation efficiency strongly, and it was found that the most efficient nanocomposites were TiO2 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 (λmax = 365 nm, Intensity = 1.8 mW/cm2) within 100 minutes. But for 50 μg/mL TiO2 nanoparticles, only 40% cancer cells were killed under the same condition