Environmental Friendly Synthesis of Silver Nanoparticles Using Leaf Extract of Mureira Tree (Azadirachta indica) Cultivated in Iraq and Efficacy the Antimicrobial Activity

In the present study, environment friendly and cost effective silver nanoparticles were synthesized using the leaves extract of Mureira tree cultivated in Iraq as the reducing and capping agent. The nanoparticless were characterized using UV-visble, FT-IR, XRD, and SEM methods. The surface plasmon resonance peaks in absorption spectra for silver colloidal solution showed an absorption peak at 420 nm in a UV-visible spectrum. The functional biomolecules such as carboxyl groups present in the seaweed responsible for the silver nanoparticles formation were characterized by FT-IR. The XRD results suggested that the crystallization of the bio-organic phase occurs on the surface of the silver nanoparticles or vice versa. The broadening of peaks in the XRD patterns was attributed to particle size effects and the average particles size about 30 nm which was calculated by using the Dubai-Scherrer equation. The silver nanoparticles synthesized by the help of Mureira tree leaves extracts were scanned using SEM. It reveals that a silver nanoparticle seems to be spherical in morphology. The results shows that silver nanoparticles synthesized by Moreira leaves extract has effective antibacterial activities on the test isolates as indicated by the diameter of their zone of inhibition. The inhibition zone was 17 mm for Enterobacter cloacae, 18 mm for Escherichia coli and Klebsiella pneumonia, 16 mm for Proteus mirabilis and Pseudomonas aeruginosa, 15 mm for Bacillus sp., Staphylococcus aureus and Streptococcus spp. The antimicrobial activity of Moreira leaves extract has lowest effect against tested isolates. The inhibition zone was 7 mm for Enterobacter cloacae, Escherichia coli, Pseudomonas aeruginosa, Bacillus sp. and Streptococcus spp. 10 mm for Klebsiella pneumonia, and 8 mm for Staphylococcus aureus.The study revealed that the silver nanoparticles synthesis by using leaves extract of Mureira tree could be as a therapeutic agent for human microbial infections. Keywords: Silver nanoparticles, pathogenic bacteria, Mureira tree, Leaf Extract, antimicrobial activity