Biosynthesis, Characterization and Antimicrobial Efficacy of Zinc Oxide Nanoparticles via Plectranthus amboinicus Leaf Extract

This study investigates the environmental friendly synthesis of zinc oxide nanoparticles using Plectranthus amboinicus leaf extract. The X-ray diffraction (XRD) analysis confirms the presence of well-crystalline ZnO nanoparticles with a crystallite size of 42 nm. Scanning electron microscopy (SEM) reveals the size, shape and distribution of nanoparticles within the extract, indicating their impact on Plectranthus amboinicus growth. Energy dispersive X-ray (EDX) analysis confirmed the high nanoparticle purity, while FTIR spectral analysis identifies the organic compounds involved in the synthesis. UV-visible absorption spectroscopy shows a reduced bandgap energy in the green-synthesized ZnO nanoparticles. Dynamic light scattering (DLS) analysis indicates a mean particle size of 11 nm with a significant stability. These nanoparticles exhibit exceptional antimicrobial activity, especially against Gram-negative bacteria. This eco-friendly synthesis method offers cost-effectiveness, safety and sustainability, promising diverse applications in the antimicrobial therapies, food preservation and water treatment, addressing various industrial challenges.