ECO-FRIENDLY SYNTHESIS, PHYSICO-CHEMICAL ANALYSIS, BIOMEDICAL APPLICATION AND PHOTOCATALYTIC ACTIVITY OF COBALT OXIDE NANOPARTICLES (Co3O4NPs) DERIVED FROM TRIBULUS TERRESTRIS L

Abstract: A green synthesis of cobalt oxide nanoparticles was accomplished by aqueous medium of the Tribulus terrestris extract, without the addition of any external chemical reducing agent. Several factors such as pH of the solution, temperature, and concentration of the added extract greatly influence the synthesized nanoparticles. The reduced cobalt oxide nanoparticles were characterized by ultra-violet–visible absorption spectroscopy (UV–Vis), Fourier transform–infrared spectroscopy (FT–IR), Fluorescence spectroscopy, XRD, Dynamic light scattering (DLS), Scanning electron microscopy (SEM) with EDS and Transmission electron microscope (TEM) analysis. Formation of cobalt oxide nanoparticles was approved from the change in color of colorless to violet and strong surface plasmon resonance (SPR) was observed at 555 nm using UV-Vis spectroscopy. The size distribution of the cobalt oxide nanoparticles was also revealed by SEM analysis. The size range of the Co3O4 NPs was from 6 to 25 nm. Similarly, particles with a distinctive peak of cobalt were examined with EDS. Moreover, the potential of the nanoparticles for biomedical applications have also been confirmed by their antimicrobial activity against Gram positive and negative bacteria. Antioxidant activity done by DPPH radical, anticancer activity of green synthesized cobalt oxide nanoparticles against with MCF-7 cell line. Finally photo catalytic activity also evaluated by methylene blue dye, really, this study provides new possibilities of using T. terrestris extract as a capping and reducing agent for the synthesis of cobalt oxide nanoparticles, which may be applicable for the future diagnostic and therapeutic fields.