Calcination temperature-driven antibacterial and antioxidant activities of fumaria indica mediated copper oxide nanoparticles: characterization

The current study was planned to synthesize copper oxide nanoparticles (CuO NPs) using aqueous Fumaria indica (F. indica) plant extract and was calcined at 100, 300, 600 and 900 degrees C using Muffle furnace. The X-ray diffraction analysis reveals that crystallinity and crystallite size increase (from 14.9 to 79.29 nm) with increasing calcination temperature. The microstructure was analyzed through scanning electron microscopy, while the constituent elements were identified through energy-dispersive X-ray. The diffuse reflectance spectroscopy analysis was carried out and the optical band gap was determined through Tauc plot, which was found to decrease (from 1.82 to 1.46 eV) with increasing calcination temperature. The surface functional moieties were identified by performing Fourier transform infrared spectroscopy. Agar well diffusion process was followed to screen CuO NPs against Gram-positive bacteria and Gram-negative bacteria, where higher activity was found against Gram-negative bacteria. The antioxidant activity of CuO NPs was evaluated during the neutralization ABTs free radical, thus it can be used to reduce the damaging effects of antioxidants.