Size-controlled and bio-directed synthesis of ceria nanopowders and their in vitro cytotoxicity effects

The use of bio-based materials such as food-directed products for the synthesis of different nanoparticles (e.g., metal and metal oxide) is of enormous interest to modern nanoscience and nanotechnology. We have developed a simple and green chemistry method with bio-directed, available, and low cost materials for the synthesis of size-controlled ceria nanopowders (CeO2-NPs) using fresh egg white (EW), as an eco-friendly foamy substrate. The proteins of EW, which have various functional groups, played important roles in the synthesis of CeO2-NPs as capping and stabilizing agents. The synthesized CeO2-NPs were characterized by the following title: UV–vis spectroscopy, field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric (TGA–DTA) analysis, and powder X-ray diffraction (PXRD). Spherical CeO2-NPs were synthesized at different calcination temperatures (200, 400, 600, 800°C) and FESEM imaging along with its corresponding particles size distribution indicated the formation of nanopowders in size of about 25nm. The PXRD analysis revealed fluorite cubic structure for CeO2-NPs with preferential orientation at (111) reflection plane. In vitro cytotoxicity studies on human periodontal fibroblasts cells showed a dose dependent toxicity with non-toxic effect of concentration up to 800μg/ml. The synthesis of CeO2-NPs in EW was found to be comparable to those obtained from conventional preparation methods that uses hazardous materials proving to be an excellent alternative for the preparation of CeO2-NPs, using food and bio-derived materials.