Abstract
In recent years, the application of selenium nanoparticles has been increasing in medicine, agriculture, engineering, and food science. Therefore, researchers are converting inorganic selenium sources into nano form by various methods. Particularly both probiotics and pathogenic bacterial strains have the ability to synthesize selenium nanoparticles under aerobic and anaerobic conditions. Amazingly, dose-dependent selenium nanoparticles have antibacterial activity against their own pathogenic producer, even when added externally. Also, plant extracts and conventional chemical reducing agents continue to make a significant contribution to the production of selenium nanoparticles in an economic, eco-friendly, simple, and rapid way. Biological and chemical methods are suitable for the biological applications of selenium nanoparticles such as functional food or nutritional supplements and nanomedicine.