Green Synthesis of Copper Oxide Nanostructures using Cynodon dactylon and Cyperus rotundus Grass Extracts for Antibacterial Applications

Copper oxide (CuO) nanostructures were synthesized using Cynodon dactylon and Cyperus rotundas grass extracts. XRD analysis revealed formation of end-centered monoclinic structured CuO with high crystallinity. SEM images of CuO nanostructure prepared by C. dactylon grass extract disclosed rice spikelet-like morphology, while CuO nanostructure synthesized by C. rotundas grass extract exhibited composite morphology with nanoparticles, nanorods and nanoprisms. EDAX spectra clearly revealed presence of Cu and O elements that confirms purity of CuO nanostructures. Strong absorption peaks observed in FTIR spectra of monoclinic CuO nanostructures revealed high purity of CuO nanostructures synthesized by grass extracts. Potential antibacterial activity exhibited by CuO nanostructures against Gram negative Klebsiella pneumoniae bacterial species with zone of inhibition of 28 mm can be ascribed to diverse factors, such as mechanical damage, oxidative injury and gene toxicity. Thus, C. dactylon and C. rotundas grass extracts can be regarded as sustainable and abundant natural resources towards green synthesis of CuO nanostructures for potential antibacterial applications.