Eco-Friendly Biosynthesis of Selenium Nanoparticles Using <i>Nigella Sativa</i> Seed Extract

Selenium nanoparticles (SeNPs) have emerged as promising materials due to their unique physicochemical properties and diverse applications in medicine, agriculture, and environmental remediation. They also serve as effective carriers for delivering drugs with antioxidant or anti-inflammatory effects, owing to their low toxicity, excellent biocompatibility, and strong antioxidant activity. Conventional chemical and physical methods for SeNP synthesis often involve hazardous reagents, high energy consumption, and environmental risks, making green synthesis approaches highly attractive. Among plant-based systems, Nigella sativa (black seed) has gained significant attention as a natural reducing and stabilizing agent for nanoparticle biosynthesis, owing to its rich phytochemical profile, including thymoquinone, polyphenols, and flavonoids. This review provides a comprehensive overview of the eco-friendly biosynthesis of SeNPs using Nigella sativa seed extract, highlighting the underlying mechanisms, optimization parameters, and characterization techniques. It also discusses the biological activities of Nigella sativa -mediated SeNPs, particularly their antioxidant, antimicrobial, and anticancer properties. Despite promising progress, challenges such as scalability, reproducibility, and limited mechanistic insights remain.