Green synthesis of CuO/MgO/ZnO nanoparticles using Costus pictus leaf extract for effective antibacterial applications.

[Display omitted] • The CuO/MgO/ZnO NPs have been successfully synthesised from the Costus pictus D. Don plant. • CuO/MgO/ZnO NPs showed inhibitory activity against different bacteria. • The negative zeta potential confirms the stability and dispersion of CuO/MgO/ZnO NPs. • The CuO/MgO/ZnO NPs have significant surface area displaying their anti-bacterial potential. In recent years, environmentally friendly methods have garnered significant attention in developing novel nanoparticles (NPs). This study focuses on the green synthesis and characterisation of CuO/MgO/ZnO NPs using Costus pictus D. Don Plant extract as a green reducing and capping agent. X-ray diffraction (XRD) analysis was employed to assess the purity of NPs, whereas Fourier-transform infrared (FTIR) and UV–Vis spectroscopy were employed to study the chemical composition and absorption peaks of the synthesised NPs. The Field-emission scanning electron microscopy (FE-SEM) images revealed a distinctive flower-like morphology of NPs, and their stability and dispersion were supported by a negative zeta potential of −14.8 mV. The significant surface area (87.742 m2/g) of CuO/MgO/ZnO NPs was obtained from Brunauer-Emmett-Teller (BET) analysis. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) analysis confirmed that the particle size of NPs is nearly 50 nm and is poly-crystalline. Finally, the synthesised NPs were tested against the bacteria using the agar-well diffusion method. Notably, CuO/MgO/ZnO NPs exhibited better antibacterial activity against Pseudomonas aeruginosa , yielding a substantial inhibition zone of 23.33 ± 2.08 mm. [ABSTRACT FROM AUTHOR]