Piper nigrum Leaf Extract Mediated Synthesis of Copper Oxide Nanoparticles and their Antimicrobial Activity Against Soil Phytopathogens

The bio-inspired synthesis of copper oxide nanoparticles using Piper nigrum leaf extract (BP-CuONPs) is reported in this study. The rapid reduction of copper (Cu2+) ions was preliminarily confirmed using a UV–Vis spectrophotometer with peak formation at 270 nm. Further-ray diffraction (XRD) patterns confirmed the crystalline phase of copper oxide with a monoclinic crystal structure. Fourier Transformed Infrared (FTIR) spectroscopy of the nanoparticles revealed the presence of various functional groups, including alcohol, phenols, carboxylic acids, and amide containing alkaloids such as piperine, which serve as reducing and capping agents for the metal nanoparticles and indicate the presence of metal oxide nanoparticles. Energy dispersive X-ray (EDX) spectroscopy revealed that the weight percentage of copper was approximately 68.29%. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the formation of spherical BP-CuONP NPs with an average particle size of 5 nm- 24.5 nm. BP-CuONPs exhibited complete inhibition against four soil-borne fungal phytopathogens at 1500ppm.