Biosynthesis is an eloquent, safe, biocompatible, eco-friendly, and recyclable way of preparing selenium nanoparticles (SeNPs). Selenium occurs in multiple oxidation states, for example, +6, +4, 0, or −2. Selenium (Se) is an essential trace element with a very narrow margin between the lowest acceptable levels of intake and toxicity. Selenium is an essential trace element required for all living organisms. Despite its essentiality, selenium is a potentially toxic element to natural ecosystems due to its bioaccumulation potential that is why it is biologically available in the environment. Selenium is a trace element commonly found in materials of the earth’s crust, and it is essential for humans, animals, and plants. Oxyanions of selenium, that is selenite and selenate, are biologically available. Selenium in the form of selenate ion (SeO42−) is more toxic to most organisms than selenite (SeO32−). Contrarily, elemental selenium (Se0) is inOsoluble and less toxic in comparison to other forms of selenium. Nanoselenium (Se0) in the range of 100–500 nm has similar bioavailability to other forms of selenium into plants, animals, humans, and microorganisms. Biologically synthesized SeNP has many biological applications in the field of medical and pharmaceutical research to combat threats to human health. Biogenic SeNPs have anticancer (cytotoxic) activity, antioxidant activity, and antimicrobial activity. Researches are going on with special interest of SeNPs. Conjugation of antibiotics with SeNPs enhances their anticancer efficacy. SeNPs have also applications in nanobiosensors and environmental remediation.
ANTIOXIDANT ACTIVITY AND BIOGENIC SYNTHESIS OF SELENIUM NANOPARTICLES USING THE LEAF EXTRACT OF ALOE VERA
