Insights into the impact of surfactants on the kinetics of selenium nanoparticles formation via lemon juice-assisted methodology, followed by their antibacterial and antioxidant assessment

Abstract

Selenium nanoparticles (Se NPs) fabrication utilizing active species of natural lemon juice represents a promising pathway in the biosynthesis of nanoparticles. The reduction of Se4+ to Se(0) could be attributed to the presence of natural lemon juice, which was considered a supplier of vitamin C, polyphenolic compounds, flavonoids, and sugars. The synthesized spherical Se NPs exhibited a characteristic surface plasmon resonance band (SPR) at λ = 320 nm. The values of the rate constant for the reduction of Se (IV) to Se (0) by lemon juice were estimated to be kobs = 0.0011 s−1 for a Se concentration of 0.75 mmol.dm−3 and a lemon content of 0.001 mol.dm−3 at room temperature. Various conditions have been studied on the kinetics of Se NPs formation, such as the doses of SeO2 and lemon juice, and the presence of cationic and/or anionic surfactants like cetyltrimethyl ammonium bromide (CTABr) and sodium dodecyl sulfate (SDS), respectively. The synthesized Se particles were characterized by physicochemical techniques such as FT-IR, XRD, TEM, DLS, and zeta potential to investigate their main functional groups, crystallinity, chemical composition, particle size, and surface morphology. Moreover, the antioxidant power of Se NPs was tested in terms of their DPPH free radical scavenging activity. Finally, the antibacterial activity of the studied nanoparticles was confirmed against gram-positive and gram-negative bacteria (Staphylococcus aureus and Pseudomonas aeruginosa, respectively). In short, this study introduced the impact of surfactants on the formation of biocompatible Se NPs as an active antibacterial and antioxidant.