A novel one-pot green synthesis of selenium nanoparticles and evaluation of its toxicity in zebrafish embryos.

Over the last 50 years, compelling evidence has accumulated on the beneficial role of selenium in human health. In the present study, different proteins were evaluated as reducing agents for the eco-friendly synthesis of selenium nanoparticles from an aqueous solution of sodium selenite. This method is a simple, low cost green synthesis alternative to chemical synthesis. The high conversion of selenium ions to selenium nanoparticles (SeNPs) was achieved by a reaction mixture of 0.1 g bovine serum albumin and 0.1 g sodium selenite at a reaction temperature of 121°C for 20 min duration. The selenium nanoparticles were characterized by fourier transform infrared (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy. The FTIR spectral bands were sharp with strong absorption peaks at 1649 and 1551 cm(-1). SEM analysis of the synthesized selenium nanoparticles clearly showed the spherical shape with an average size ranging from 500 to 600 nm. The toxicity of SeNPs was evaluated using zebrafish embryos as a model system. SeNPs induced malformations in zebrafish embryos in a concentration-dependent manner. Selenium nanoparticles at 15-25 μg/ml concentration caused pericardial edema, tail malformation and decrease in heart rate in zebrafish embryos. Treatments with lower concentrations did not alter the heart rate or display any heart abnormalities. This study underlines the importance of identifying optimal SeNP concentration that could have potential therapeutic applications.