Structural and optical properties of copper oxide nanoparticles: A study of variation in structure and antibiotic activity

In this paper, we study the synthesis dependence of structural, optical and antimicrobial properties for copper oxide nanoparticles on, synthesized using microwave irradiation CuO(M), co-precipitation CuO(P) and hydrothermal CuO(H) protocols. Structural and morphological properties were studied using XRD, SEM, TEM and SAED techniques. XPS studies confirmed the presence of copper ions in Cu2+ oxidation state, and Raman spectroscopy confirmed the presence of nanostructured phase in all the samples. The synthesized CuO(M), CuO(P) and CuO(H) nanoparticles were investigated for antimicrobial activity against different pathogenic bacteria including methicillin-resistant Staphylococcus aureus. The result showed that maximum inhibition zone was detected in CuO(M) nanoparticles against Gram-negative bacteria i.e. Klebsiella pneumoniae (20 mm). CuO(H) and CuO(P) nanoparticles have antibacterial inhibition zone of 17 mm and 13 mm against K. pneumoniae and S. aureus, respectively. The CuO(P) and CuO(H) nanoparticles displayed mild antimicrobial activity as compared to the CuO(M) nanoparticles.