Green synthesis and evaluation of metabolic activity of starch mediated nanoceria

Crystalline nanoceria powders have been synthesized by green-mediated sol–gel method in aqueous solution. The cerium nitrate hexahydrate as precursor and starch were taken in water and precipitated with ammonium hydroxide at pH 10. To terminate the growth of nanoceria particles and also to stabilize them, long-chain starch molecules were utilized. The sample was then calcined for 2 h in a temperature range of 120–600 °C and characterized by the number of techniques, including powder X-ray diffraction (PXRD), UV–vis spectrophotometry, and high-magnification transmission electron microscopy (TEM). The particle size obtained from TEM was in the range of 6 nm with uniform shape and narrow particle size distribution. The diffraction pattern completely indexed with the cubic fluorite structure of CeO2. The calcined nanoceria powders showed strong UV absorption. In vitro cytotoxicity studies on Neuro2A cells showed a dose dependent toxicity with non-toxic effect of concentration up to 175 µg/mL. The results show that starch is an interesting material that can be used as a stabilizer in the sol–gel processes for preparing small nanoceria particles.