Green synthesis and characterization of Fe, Cu and Mg oxide nanoparticles using Clematis orientalis leaf extract: Salt concentration modulates physiological and biological properties

Abstract Green synthesis approach to manufacture metal oxide nanoparticles (MONPs) have gained attention due to marvelous properties governed by the synergistic effects of metal and phyto-constituents. We report green chemistry method for extracellular synthesis of Copper (CuO), Magnesium (MgO) and Iron oxide (FeO) nanoparticles using Clematis orientalis leaves extract. Copper acetate, magnesium sulfate and ferric chloride (0.25 and 0.5 M each separately) were reduced by leaves extract of C. orientalis to synthesize respective MONPs. The theoretical size of MONPs calculated using XRD data was 13–53 nm. The purity of MONPs was confirmed through EDS while SEM analysis confirmed crystalline nature of CuO and FeO NPs, however MgO NPs were crystalline cum amorphous in nature. MONPs synthesized at low salt concentration (0.25 M) revealed better free radical scavenging activity, reducing power potential, and total antioxidative capacity. While phenolic and flavonoid like activities on MNOPs were better when synthesized at 0.5 M salt concentration. MONPs exhibited significant antibacterial activity (10–23 mm) against Gram-positive and Gram-negative bacterial strains. The study concludes that concentration of salt used for synthesis of MONPs has the influential role in determining physiological and biological properties of MONPs. Furthermore, C. orientalis functionalized MONPs can be used for medical applications due to antibacterial and antioxidative capabilities.