Bloom to Bioactive: Environmentally Benign Biosynthesis and Characterization of Silver Nanoparticles Mediated by Mangifera indica Flower Bud Extract and Evaluation of Their Antibacterial and Antifungal Activity

Abstract

Background: For the first time, plant-derived silver nanoparticles (SNPs) were synthesized from Mangifera indica flower buds using a green nanotechnology approach. Numerous phytoconstituents present in M. indica are well recognized for their diverse medicinal properties. This study presents a sustainable and non-toxic biogenic strategy for the development of nanoformulations with potential therapeutic applications. Objective: The aim of this research was to synthesize plant-based silver nanoparticles using aqueous extracts of M. indica flower buds collected from three mango orchards in the Banswara district of Udaipur, Rajasthan. The study further sought to characterize the synthesized nanoparticles and evaluate their antimicrobial efficacy against a panel of pathogenic microorganisms. Methods: The biosynthesized silver nanoparticles were characterized using multiple analytical techniques. Antimicrobial activity was evaluated against pathogenic microbial strains using the disc diffusion method. Phytochemical constituents were qualitatively analyzed. Statistical analysis was performed using one-way ANOVA, and p-values <0.05 were considered statistically significant. Results: UV–Visible spectroscopy confirmed SNP formation, showing a characteristic surface plasmon resonance peak at 430–440 nm. Powder X-ray diffraction analysis revealed a crystalline structure with a face-centered cubic lattice and an average particle size of 10.45 nm. FTIR analysis identified functional groups involved in the reduction and capping of silver ions, which was further supported by phytochemical analysis. SEM and EDX analyses demonstrated predominantly spherical to flaky nanoparticles ranging from 82–86 nm, with silver as the major elemental component. The highest antimicrobial activity was observed against Escherichia coli, Pseudomonas aeruginosa, and Candida glabrata, particularly at higher SNP concentrations compared with the control drug. Conclusion: The findings indicate that M. indica flower buds are a promising biological source for the green synthesis of silver nanoparticles. Notably, the ability of flower-bud-derived SNPs to inhibit pathogenic microbial growth at relatively low concentrations, compared with conventional antibiotics, highlights their potential application as effective biogenic antimicrobial agents.