Phytofabrication of Selenium-Silver Bimetallic Nanoparticles Using Echinacea purpurea Extract: Characterization and Antioxidant Activity

The phytofabrication of selenium-silver bimetallic nanoparticles (Se-Ag BNPs) utilizing Echinacea purpurea aqueous extract is investigated in this study. The synthesis process is characterized by a visible color change to dark reddish brown, a sign indicating successful nanoparticle formation. UV-visible spectrum analysis confirms the presence of SeNPs and AgNPs with absorption maxima at 268 nm and 325 nm, respectively. X-ray diffraction (XRD) patterns reveal the crystalline structure of the synthesized Se-Ag BNPs, exhibiting characteristic peaks consistent with metallic silver and selenium nanoparticles. Transmission electron microscopy (TEM) analysis showcases the diverse morphological structures of the Se-Ag BNPs, predominantly spherical but also featuring hexagonal and oval shapes. The average particle size is determined to be 33.38 nm, indicating uniformity and stability. Furthermore, the antioxidant properties of Se-Ag BNPs are evaluated through DPPH and ABTS radical scavenging assays, demonstrating dose-dependent scavenging capabilities with IC50 values of 264.78 µg/mL and 344.19 µg/mL, respectively. These findings underscore the potential of Se-Ag BNPs as effective antioxidants, offering promising applications in various fields such as biomedicine and environmental remediation. Comparisons with previous studies highlight the efficacy of the biosynthesis method using Echinacea purpurea extract in producing Se-Ag BNPs with superior antioxidant activity.