Green Synthesis of Silver Nanoparticles Using Aqueous Extracts of Fruit Peel: Antioxidant, Antimicrobial and Photocatalytic Activities

Abstract

The increasing threat of multidrug-resistant pathogens and the growing environmental burden of agricultural waste have prompted the search for sustainable solutions. Green synthesis utilizing fruit peel extracts offers an environmentally benign approach for producing biologically active nanomaterials with therapeutic and environmental remediation potential. Herein, silver nanoparticles (AgNPs) were fabricated using aqueous extracts derived from pomegranate, lemon, and orange peels. The synthesized nanomaterials were subsequently characterized through UV-Vis, FTIR, and SEM. Characteristic absorption maxima between 425-450 nm confirmed nanoparticle formation, while SEM micrographs revealed predominantly spherical morphologies. FTIR analysis identified characteristic O–H, C–H, C=O, and C–O bands, indicating that polyphenols and flavonoids in the fruit peel extracts served dual functions as both reducing and capping agents during nanoparticle synthesis. The antioxidant property measured through the DPPH free radical scavenging assay showed the highest antioxidant ability for pomegranate AgNPs (62.92%). The biosynthesized AgNPs displayed noteworthy antimicrobial efficacy against both gram positive (S. aureus and B. subtilis) and gram negative (E. coli and P. aeruginosa) bacteria. Moreover, the maximum inhibition zone of 19.6 mm (against S. aureus) was achieved using pomegranate-derived AgNPs (P-AgNPs). In addition, the AgNPs efficiently degraded crystal violet under sunlight, achieving maximum degradation efficiencies of 89.91%, 93.62%, and 93.55% for P-AgNPs, O-AgNPs, and L-AgNPs, respectively. Sustainable valorization of agricultural waste via the proposed method results in nanoparticles with multifaceted applications while simultaneously contributing to the reduction of solid waste