Eco-Friendly Synthesis and Physicochemical Characterization of Silver Nanoparticles Mediated by Eugenia roxburghii DC. Extract with Antibiofilm Efficacy against Pathogenic Bacteria

The increasing resistance of bacteria to conventional antibiotics necessitates the exploration of alternative antimicrobial strategies. This study presents a green, eco-friendly synthesis of silver nanoparticles (AgNPs) using methanolic leaf extract of Eugenia roxburghii DC., a medicinal plant known for its rich phytochemical content. The synthesized AgNPs were characterized by UV–Visible spectroscopy, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), and zeta potential analysis. A distinct surface plasmon resonance peak at 417 nm confirmed nanoparticle formation, while XRD and HR-TEM analyses revealed a crystalline, predominantly spherical morphology with an average particle size of 24–35 nm. The AgNPs exhibited strong antibacterial activity, particularly against Staphylococcus aureus, as demonstrated by disc diffusion and minimum inhibitory concentration (MIC) assays. Furthermore, the nanoparticles significantly inhibited biofilm formation, as observed on Congo Red Agar plates. These findings underscore the potential of E. roxburghii-mediated AgNPs as a sustainable and biocompatible alternative for combating pathogenic bacteria and biofilm-related infections. Future in vivo and toxicological studies are warranted to evaluate clinical applicability.