Enhancement of Photocatalytic Cancer Cell-Killing Activity by Using Ag@TiO2 Core-Shell Composite Nanoclusters
M. Abdulla-Al-Mamun, H. Yang, Y. Kusumoto
Kagoshima University, JP
Keywords: Ag@TiO2, core-shell nanocomposite, photocatalytic, HeLa cell
Abstract:The photocatalytic cancer cell-killing activities of the Ag@TiO2 core-shell composite colloidal nanoclusters have been investigated on HeLa cells killing under the UV-visible light irradiation. The Ag metal core-TiO2 shell (Ag@TiO2) composite nanocluster photocatalyst with uniform size, shape and core-shell structures were successfully synthesized by a simple citrate reduction method. The photocatalytic cell killing activities of the Ag@TiO2 nanoclusters were found to vary with Ag to TiO2 molar ratios. The direct involvement of the metal particles in mediating the electron transfer from the photoexcited TiO2 under the band gap excitation is considered to carry out the efficient photocatalytic reaction on the cells. The charge separation and interfacial charge-transfer promote the photocatalytic cancer cell killing more than the TiO2 semiconductor alone. It was found that the Ag@TiO2 nanoclusters under the low concentrations kill HeLa cells by 100%, whereas TiO2 nanoparticles alone kill only ca. 25% under the same concentrations.