Using different calcination temperatures and solvents to assess the synthesized CuO NPs as an anti-bacterial agent

Nanoparticles based materials are an emerging field that is studied as an antibacterial agent to overcome multidrug resistance bacteria. Chemical precipitation method which is cost-effective and simple had been used for the synthesis of CuO NPs. The effect of solvent (water and ethanol) and calcination temperature (1000, 250° and 400° C) on the characteristics of CuO nanoparticles were investigated. The prepared CuO NPs characteristics were studied by Fourier transform infrared analysis (FT-IR ), Ultraviolet-Visible spectroscopy (UV-VIS), Energy Dispersive X-ray( EDX) and X-ray diffraction (XRD). Different concentrations (25 ,75 ,100 and 150 µg/mL) of CuO NPs were used to evaluate their antibacterial activity against Gram-negative( Pseudomonas aeruginosa ) and Gram- positive (Staphylococcus aureus) bacterial strains using 96 microtiter plate technique. The alcoholic chain of ethanol when it was used as a solvent instead of water, made the size of CuO NPs smaller at the same calcination temperature (12.10, 15.03,23.79 nm) and(13.50,17.43,28.57nm) respectively. The chemical composition and purity of the prepared samples of CuO NPs were verified by FT-IR and EDX with weight percentage for Cu was 64-77wt % and for O was 19-28 wt%. Very good Inhibition activity against Pseudomonas aeruginosa and staphylococcus aureus was found depending on 96-well microtiter plate technique (Statistically significant at P≤ 0.05), and it was correlated with the size and concentrations of nanoparticles. The maximum inhibition rate of bacteria was obtained in the smallest size of CuO NPs with maximum concentration when ethanol was the solvent ( 90% inhibition rate for Staphylococcus aureus and 80% inhibition rate for Pseudomonas aeruginosa at particle size 12.1 and 150 µg/mL concentration of CuO NPs).