Green Synthesis of CuO Nanoparticles Using Leaf Extract of Catha edulis and Its Antibacterial Activity

Abstract

Copper oxide nanoparticles (CuO NPs) have attracted huge attention due to catalytic, electric, optical, photonic, and antibacterial activity. The use of plant leaf extracts in the biosynthesis of nanostructured materials is an eco-friendly, non-toxic and cost effective approach. Hence, this study aims to provide an updated survey of the main green synthesis method of CuO NPs using leaf extract of Khat, its characterization and studies on antibacterial activities. The synthesis of CuO NPs was done by reducing 1 mM CuSO 4 5H 2 O with 2% (m/v) aqueous leaf extract of Khat under optimum conditions (pH = 11). The formation of CuO NPs has been confirmed first by the color change from colorless to light green and then to greenish yellow. The kinetics of the reaction was studied using UV-Visible (UV-Vis) spectrophotometer that showed surface plasmon resonance at 333 nm. The CuO NPs exhibit antimicrobial activity against two human pathogens viz. Salmonella typhimurium and Escherichia coli with an average zone of inhibition of 12.5 mm and 8 mm, respectively. Therefore, the current study reveals a convenient utilization of Catha edulis extract as a reducing agent for the successful synthesis of CuO NPs through a green synthesis method to obtain significantly active antibacterial material.