Antimicrobial and scavenging potential of green synthesized silver/manganese bimetallic nanoparticles using <i>Euphorbia cactus</i> extract

The fabrication of novel nanomedicines in the pursuit of alternative therapeutics has increasingly embraced eco-friendly strategies. This study reports the phytogenic synthesis of bimetallic silver-manganese nanoparticles (Ag/MnNPs) through bio-reduction using non-toxic extract from aerial part of <i>Euphorbia cactus</i> as a sustainable and environmentally benign reducing and stabilizing agent. Advanced spectroscopic and microscopic characterization techniques were applied to elucidate the physico-chemical features of green synthesized <i>Euphorbia cactus</i>-mediated Ag/MnNPs (EC-Ag/MnNPs). The formed EC-Ag/MnNPs were predominantly spherical and uniform, with an average size of 18.32 nm. Fourier transform infrared spectroscopy (FTIR) analysis revealed the existence of multiple functional groups, indicating the involvement of <i>Euphorbia cactus</i> phytoconstituents in the synthesis, reduction and stabilization of EC-Ag/MnNPS. The energy-dispersive X-ray (EDX) estimation confirmed the elemental composition, showing 43.62% of silver and 18.71% manganese content. Both biogenic bimetallic EC-Ag/MnNPs and <i>Euphorbia cactus</i> (EC) extract exhibited excellent antimicrobial and scavenging potential. The bimetallic EC-Ag/MnNPs exerted superior antibacterial efficacy, with maximum inhibition zones of 38.15 ± 0.32 mm against <i>Escherichia coli</i> and 36.81 ± 0.51 mm against <i>Salmonella Typhi</i>. EC-Ag/MnNPs also showed remarkable antifungal efficacy against <i>Candida glabrata</i> (35.10 ± 0.39 mm) and <i>Candida parapsilosis</i> (33.82 ± 0.97 mm). Additionally, the biosynthesized EC-Ag/MnNPs showed strong, dose-dependent antioxidant activity, achieving a maximum scavenging efficiency of 96.12% at a concentration of 80 µg/mL. The results demonstrated significant antimicrobial and antioxidant properties of green-synthesized EC-Ag/MnNPs, underscoring their potential application in antimicrobial formulations and enhancement of medical device functionality.