Synthesis and characterization of manganese dioxide nanoparticles using neem leaf extract and evaluation of their antibacterial activity
Year: 2026
Type: article
Abstract: Green synthesis of metal oxide nanoparticles has emerged as a sustainable alternative to conventional chemical methods for producing functional nanomaterials with biomedical applications. In this study, manganese dioxide (MnO₂) nanoparticles were synthesized using aqueous neem ( Azadirachta indica ) leaf extract as a natural reducing and stabilizing agent. Response Surface Methodology (RSM) based on a Box–Behnken design was employed to optimize the synthesis conditions. The optimum conditions were identified at 52.05 °C, pH 9.68, and 115.04 min, yielding a predicted absorbance of 1.872 a.u., which was experimentally validated. The synthesized nanoparticles exhibited a characteristic absorption peak at 310 nm, an average hydrodynamic particle size of 66.63 nm, an average crystallite size of 38.35 nm, and a zeta potential of −30.7 mV, indicating good colloidal stability. Structural and morphological analyses confirmed the successful formation of crystalline MnO₂ nanorods stabilized by phytochemicals present in the neem extract. The biosynthesized MnO₂ nanoparticles demonstrated antibacterial activity against both Escherichia coli and Staphylococcus aureus , producing inhibition zones of 14 ± 0.62 mm and 9 ± 0.40 mm, respectively, with greater effectiveness against the Gram-negative bacterium. These findings demonstrate that neem-mediated green synthesis, combined with statistical optimization, provides a simple, eco-friendly, and reproducible route for producing stable MnO₂ nanoparticles with promising antibacterial properties and potential applications in antimicrobial materials and environmental technologies.
Source: Next Materials
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,280
OpenAlex ID: W7221808024