Green Synthesis and Morphology Dependent Antibacterial Activity of Copper Oxide Nanoparticles

Copper oxide nanoparticle (CuO-NPs) has been widely utilized in biomedical application due to its antibacterial function. The aim of this study is to synthesis CuO-NPs with various morphologies, using Aloe Vera extract as reducing agent and investigate their antibacterial properties. Results demonstrated the formation of pure CuO-NPs with crystallite size in range of 9-23 nm, depending on the precursor type and concentration as well as aging time. Increasing the aging time from 0 hr to 72 hr resulted in changing the morphology of particles from sharp edge to spherical form. Furthermore, decreasing the Cu+/OH- ratio altered the morphology of nanoparticles from spherical to rod shape. We also examined the inhibitory effects of CuO-NPs toward the gram-negative bacterium, Escherichia coli (E. coli ) and a gram-positive bacterium, Staphylococcus aureus (St. aureus ). Based on our data , while CuO-NPs had significant growth inhibition, this property depended on the morphology and size of particles. Rod and platelet shape CuO-NPs were the most effective morphologies due to the largest surface area and highest reactivity in contact with bacteria. Results also demonstrated that while all CuO-NPs were toxic to both organisms , Gram positive bacteria like St. aureus was more resistant to CuO-NPs than Gram-negative like E. coli. Together, these results suggested that morphology and shape dependent antimicrobial activity of CuO-NPs could be provided from an eco-friendly biosynthesize approach, which may be useful for biomedical application.

Keywords:

Copper nanoparticles , Morphology , Antibacterial activity , Biosynthesize approach