Highly facile and rapid one-pot synthetic protocol for the formation of Se nanoparticles at ambient conditions with controlled phase and morphology: role of starch and cytotoxic studies

Herein, Selenium nanoparticles were synthesized in aqueous solution by a one-pot, rapid, and facile methodology using sodium selenite as the precursor at ambient conditions in the presence of 1 -thioglycerol, which simultaneously played the role of a reducing as well as a capping agent. The nanoparticles were crystalline in nature, as was indicated from their XRD pattern. However, despite possessing the highly advantageous properties/applications, especially in the biological field and electronics, the thermodynamically unstable nature of amorphous Se enables its rapid phase transformation. In this perspective, a very simple approach has been applied to control the phase transformation of Se nanoparticles by using starch in the reaction mixture. Consequently, amorphous Se nanoparticles are formed predominantly, which otherwise require meticulous procedures to stabilize them. Furthermore, a reaction mechanism for the formation of these nanoparticles has been proposed. Cytotoxicity effects of both the nanoparticles were evaluated in Chinese Hamster Ovary (CHO) epithelial cells and human lung cancer cells (A549) which indicated a significantly lower percent of cytotoxicity for the crystalline and amorphous Se, as compared to the sodium selenite in the both normal and cancer cells. Notably a-Se exhibited significantly higher cytotoxicity in the cancer as compared to normal cells.