Biosynthesis of Crystalline Selenium Nanoparticles Using Rhizospheric Bacillus cereus from Mica-Rich Agricultural Soil

Selenium (Se) is an essential micronutrient with well-documented biological importance and diverse functional roles. 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 FE-SEM and TEM imaging confirmed predominantly hexagonal nanoparticles with an average diameter of 43.2 ± 21.6 nm (TEM) and 43 ± 224 nm (SEM). The findings highlight the potential of this biosynthesized approach for producing nanoscale SeNP with desirable structural properties. Future studies will focus on evaluating the stability, biological activity, and agricultural or biomedical applications of the synthesized SeNPs.