Eco-Friendly Synthesis and Characterization of Crystalline Selenium Nanoparticles via Bacillus cereus

Abstract Among all the micronutrients, selenium (Se) is highly desirable as a dietary supplement, with the potential to improve germination and seedling development in crops, as well as exhibiting anticancer and antimicrobial properties. Organic and elemental nanoforms of Se demonstrate greater reactivity, higher bioavailability, and lower toxicity compared to inorganic forms. This study proposes the biosynthesis of selenium nanoparticles (SeNPs) using a soil-borne bacterium (Bacillus cereus). The synthesis of SeNPs through rhizospheric bacteria isolated from mica-rich agricultural soil is more environmentally friendly and cost-effective than conventional chemical synthesis methods. The synthesized nanoparticles were purified, dried, and initially characterized by UV-VIS spectroscopy, which showed a prominent peak at 282 nm, a characteristic feature of SeNPs. The crystalline phases were further confirmed by matching the XRD results with the JCPDS reference code 06–0362. Surface characterization was carried out using FTIR and XPS analyses, and the size and morphology of the particles were finally confirmed by FE-SEM and TEM imaging. The environmentally sustainable biosynthesis of SeNPs by Bacillus cereus from mica-rich rhizospheric soil produces extremely stable, bioavailable, and low-toxicity nanoparticles with potential applications in agriculture.