Green synthesis and characterization of copper nanoparticles using Eryngium caucasicum Trautv aqueous extracts and its antioxidant and antimicrobial properties

Green synthesis of metallic nanoparticles has been expanding due to its potential in development of new technologies and has become an important branch of nanotechnology. Synthesis of copper nanoparticles (CuNPs) was carried out using aqueous extract of Eryngium caucasicum Trautv and confirmed by UV-visible spectroscopy, FTIR spectra, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The FTIR spectra of CuNPs indicated that the existence of flavonoids and phenolic functional groups could reduce the Cu2+ ions to CuNPs. The XRD pattern represented the crystalline nature of CuNPs and SEM analysis showed the nanoparticles with nearly spherical shapes and sizes of less than 40 nm. The antioxidant activity of CuNPs, aqueous extract and BHT were, respectively, 40.02, 58.98, and 90.12% based on the DPPH method. In addition, CuNPs and the aqueous extract of the plant demonstrated suitable antimicrobial properties against Escherichia coli, Salmonella typhimurium, Bacillus cereus and Staphylococcus aureus studied by two methods of disc diffusion and broth dilution methods. In sum, results confirmed that the use of aqueous extract of E. caucasicum Trautv has a significant potential for developing clean, easy, cost effective and efficient method for green synthesis of copper nanoparticles.