Green synthesis of silver nanoparticles using Cuminum cyminum leaf extract and evaluation of their biological activities

The aim of this study is to determine some phytochemical contents, to synthesize silver nanoparticles AgNPs using Cuminum cyminum (C. cyminum) leaf extract, to study the effects of different conditions on the rate of synthesis, and to evaluate their antibaterial and antifungal activities. AgNPs were synthesized using C. cyminum leaf extract as bioreducer agent and aqueous silver nitrate solution (AgNO3) as precursor at different conditions. The synthesized AgNPs were characterized using Ultraviolet-visible absorption spectroscopy (UV-vis), Scaning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). In addition, the synthesized AgNPs were evaluated for their antibacterial and antifungal activities against 4 positive and negative bacteria using agar disc diffusion method and the fungus Fusarium oxysporum cultivated in Potatoes Dextrose Agar (PDA) medium, respectively. Results showed that the bioreduction process was quite fast and the synthesized AgNPs were nearly spherical in shape and the size range of 3-20 nm. The AgNPs formation was affected by different parameters including concentration of AgNO3 solution and the extract, temperature and the time of reaction. The best condition for AgNPs biosynthesis was achieved by 1-3 mM AgNO3 at 40 °C after 4 h. In addition, the leaf extract and AgNPs showed efficient antibacterial activites against Gram positive and negative bacteria, respectively.