Antibacterial, Antioxidant and Physicochemical Properties of Pipper nigram Aided Copper Oxide Nanoparticles

Abstract

The Pipper nigram (P. nigram) leaf extract was used for the biosynthesis of copper oxide nanoparticles (CuO NPs) and the successful formation of the resultant product was confirmed through several physicochemical techniques. The chemical structure and the elemental composition were analysed through Fourier transform infrared (FTIR) and energy dispersive X-ray (EDX) spectroscopies, respectively. The crystalline structure and crystallite size were investigated through an X-ray diffractometer (XRD) and a monoclinic crystallite with a size of 40.68 nm was reported. Even-distributed particles with an average particle size of 49.75 nm were seen in the scanning electron micrograph (SEM), whereas the thermal stability was checked during the thermogravimetric analysis (TGA). The ultra-violet and visible (UV-Visible) spectroscopy was operated to study the light absorbance phenomena and to determine the band gap energy from the absorption edge, which was found to be 1.47 eV. The CuO NPs were used as antibacterial agents against gram-negative bacteria (GNB) and gram-positive bacteria (GPB), and greater inhibition zones were seen against the former one. The antioxidant test was also carried out against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals and the antioxidant potential of CuO NPs was found to be higher than ascorbic acid.