حيدر عباس عبدالرضا ثنوان

The study was conducted in the Faculty of Sciences / University of Kufa from 2/2/2018 to 1/5/2019.Biosynthesis of silver nanoparticles using aqueous, flower extracts of Calendula officinalis (L.) was firstly indicated by the color change of reaction mixture from yellow into reddish brown. Concentration10mM of AgNO3 and time of incubation 24 hours was done .The characterization of biosynthesized nanoparticles was achieved using UV- Spectrophotometer is a proven technique for the analysis of the nanoparticles .In Scanning electron microscope(SEM) (The shape was spherical and homogenous and the size was ranged between (63-100nm) of silver nanoparticles synthesized by plants C. officinalis. X-ray diffraction(the determination of average size of biogenic silver nanoparticles for C. officinalis was (16.73)nm, while for the commercial AgNO3 was (63)nm . FTIR spectroscopy analysis showed the presence of flavonoids, polyphenols and amide groups likely to be responsible for the green synthesis of silver nanoparticle. Antioxidant activity of silver nanoparticle of extract were investigated at 330, 230 and 55 µg/ml that have efficient to reduction absorbance of free radicals. The largest inhibition titer was found in the mixture of DPPH with AgNPs biosynthesis from C.officinalis at the concentration 1.5mg/ml(91%) ; while the smallest inhibition titer was found in the mixture of DPPH with AgNPs biosynthesis from C.officinalis at the concentration 0.5mg/ml(65%)