Structural, optical and cytotoxic behavior of titanium dioxide nanoparticles and its nanocomposites with zinc oxide

Abstract

Different metallic oxide nanoparticles showed cytotoxicity against various types of cancerous cells. The cytotoxicity mostly depends on the reactive oxygen species (ROS) generation. For that purpose, TiO2 and ZnO nanoparticles have been synthesized by chemical route. Additionally, the ZnO was deposited on TiO2 to prepare nanocomposites ZnO@TiO2 .The Prepared nanoparticles (NPs) were characterized for their structural, morphological, optical and cytotoxicity behaviour by using techniques by  X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Visible spectroscopy and ROS generation .Their structural properties indicate the anatase phase of TiO2 while ZnO formed has shown hexagonal wurtzite structure. The SEM images showed that TiO2 NPs are formed in very small and uniform spherical morphology while ZnO formed in the form of small nanorods. Both types of morphology are visible in the ZnO@TiO2 nanocomposites as well. The optical energy band gap values show the reduction in the band gap of TiO2 when it’s composite has been made with ZnO nanorods. The anticancer activity was checked through ROS generation, MTT assay was used for this purpose. The results show almost uniform ROS generation in case of TiO2 and ZnO nanostructures but it shows a reduction in ROS generation in case of ZnO@TiO2 nanocomposites. This result may be related to the less available surface area for the individual particles of one type for ROS generation