Eco-friendly synthesis of silver nanoparticles using Adansonia digitata L., leaves and evaluation of their antibacterial and antioxidant activities

This primary purpose of this study was to synthesize ecofriendly silver nanoparticles (AgNPs) using aqueous extracts from Adansonia digitata leaves. Plant bioactive molecules facilitated the conversion of silver ions through a reduction mechanism, producing stable nanoparticles confirmed by a distinct color shift observed in the reaction medium. The optical absorbance of silver nanoparticles aligned with their surface plasmon resonance peak observed within the 423–429 nm wavelength range, serving as preliminary confirmation for AgNPs synthesis within the broader 400–450 nm spectrum. The FTIR analysis identified key functional groups including flavonoids, phenolics, and proteins responsible for reduction and stabilization processes. XRD analysis revealed crystalline structures with diffraction peaks consistent with cubic crystal forms, and SEM imaging showed predominantly spherical morphology. Elemental analysis and EDS spectrum confirmed silver as the primary component. The resulting AgNPs exhibited considerable antibacterial effectiveness against gram-negative and gram-positive bacterial species. The improved antimicrobial performance was linked to their small dimensions and extensive surface area, enabling enhanced contact with bacterial cell walls. Antioxidant evaluation using DPPH assays revealed notable activity in both plant extracts and AgNPs, with leaf-derived nanoparticles exhibiting the highest scavenging ability (100 µg/ml concentration). Low IC50 values indicated strong antioxidant capacity, highlighting potential for oxidative damage reduction. This environmentally friendly synthesis method offers a sustainable alternative for AgNPs production with promising large-scale applications across multiple industries. The dual antimicrobial and antioxidant properties of the biosynthesized nanoparticles underscore their significant potential in biomedical and industrial applications, demonstrating the effectiveness of plant-mediated green synthesis approaches. This study highlights A. digitata as a promising bioresource for nanomaterial synthesis with dual biomedical benefits.