Harnessing <i>Ageratum conyzoides</i> weed for eco‐friendly synthesis of ZnO nanoparticles for antibacterial potential

Abstract Nanoparticles have gained significant attention in recent years due to their versatile applications in various fields. Among them, zinc oxide (ZnO) nanoparticles are particularly recognized for their antioxidant, antimicrobial, and anticancer properties. In this study, we report the green synthesis of ZnO nanoparticles using the invasive weed Ageratum conyzoides as a bioreducing and stabilizing agent. Zinc sulfate heptahydrate was employed as the metal precursor in an environmentally friendly and waste‐free process. The FTIR spectrum confirmed the presence of functional groups responsible for stabilizing the nanoparticle. SEM analysis revealed a predominantly spherical morphology, while XRD confirmed an average crystallite size of 54.43 nm. The nanoparticles demonstrated significant antibacterial activity against both Gram‐positive ( Bacillus cereus ) and Gram‐negative ( Pseudomonas aeruginosa and Escherichia coli ) bacteria. At a concentration of 60 µg/µL, the nanoparticles exhibited maximum zones of inhibition of 19, 16, and 15 mm, respectively, indicating concentration‐dependent antimicrobial efficacy. This study not only provides a sustainable route for the synthesis of ZnO nanoparticles but also offers a practical use for the invasive weed A. conyzoides , thereby mitigating its ecological impact. The findings highlight the potential of A. conyzoides‐ mediated ZnO nanoparticles as eco‐friendly antimicrobial agents with promising applications in biomedical and environmental fields.