Optimising Biosynthesis of Antimicrobial Copper Nanoparticles Using Aqueous Aegle marmelos Leaf Extract-Based Medium

Copper oxide nanostructures have garnered significant attention in nanotechnology for their diverse applications. This study presents a green synthesis approach using an aqueous Aegle marmelos leaf extract-based medium to produce copper oxide (Cu₄O₃) nanoparticles. Optimisation was achieved through a simplified Taguchi L9 orthogonal array, investigating critical parameters such as temperature, surfactants (AOT and Tween 80), and additives (ascorbic acid and chitosan). Under optimised conditions (AOT: 0.0012 mM, ascorbic acid: 10 mM, chitosan: 1 %, temperature: 80 °C), near-spherical nanoparticles of ~200 nm were obtained. Comprehensive characterisation through UV-Vis, DLS, electron microscopy, XRD, and FTIR spectroscopy confirmed the nanoparticles’ properties, while antibacterial assays showed promising results against Escherichia coli bacteria.