BIOSYNTHESIS OF SILVER NANOPARTICLES USING MELIA DUBIA LEAF AQUEOUS EXTRACT AND ITS ANTIBACTERIAL ACTIVITY   Submitted by: Under the Guidence of G.Dayana Jeyaleela Dr.J.Rosaline Vimala Ph.D Research scholar, Assistant professor PG & Research Department of chemistry, PG & Research Department of chemistry, Holy cross college,trichy-1 Holy cross college,trichy-1

INTRODUCTION: Synthesis of nano particles can be performed using a number of chemical and physical methods. synthesis of nanoparticles using green synthesis method. APPLICATIONS: pharmaceutical, electronics,food and feed, biomedical science, drug and gene delivery, chemical industry,cosmetics, mechanics space industries and treatments of infection cancer, allergy, diabetes and inflammation. AIM OF THE WORK: To synthesize the silver nanoparticles by using a plant leaf extract of Melia dubia biosynthesized AgNPs were characterized by using UV-Vis analysis, FTIR, XRD and SEM analysis To study the Antimicrobial activity of the silver bio-nanoparticles

MATERIALS AND METHODS: Preparation of Melia dubia leaf extract: collection of plant -leaves were dried under sunshade -powdered -plant powder and 100 ml of distilled water - boil at 60°C for 30 min then filtered through Whatman No.1 filter paper Synthesis of AgNPs: Aqueous solution (3 mM) of silver nitrate was prepared-25 ml solution & leaf extract was added -mixture was then kept on magnetic stirrer-colour change -time and colour change were recorded . Characterization Techniques: The formation of silver natenoparticles confirmed by following techniques UV-Vis , FTIR,SEM,XRD Anti Bactirial Activity: disc diffusion method

Profile of the Melia dubia Melia dubia flowers & leaves Family: Meliaceae Genus: Melia Species: M. dubia Tamil : malai veembu Uses of M.dubia Synthesis of silver nanoparticles using leaves of melia dubia

RESULTS AND DISCUSSION: UV-Visible Spectral Analysis: UV-Vis spectra were taken at different time period for 3mm AgNO3 solution (30mins to 6hrs). The spectra showed the peak approximately at 438.00nm, clearly indicating the formation of spherical AgNPs in the aqueous extract of Meliadubia. Figure- 1: UV- Visible spectra were taken at different time period for 3mm AgNO3 solution (30mins to 6hrs)

FTIR analysis: FTIR graph of AgNO3 FTIR graph of Leaf extract of Melia dubia FTIR graph of Synthesized AGNPs

OH stretching cm-1 C=O stretching cm-1 N-H stretching cm-1 C-Cl stretching cm-1 C=N stretching cm-1 CH stretching cm-1 N-O stretching Other details Silver nitrate 3467.77 1632.11 3432.97 3467,1357.7,653.61 Plant extract 3353.27 1361.84 670.34 2820.23, 1613.29 , 771.14 29929.331072.44 AgNPs 2085.60 3425.67 1639.86 1119.05 676.23 for CH2 & CH3 deformation plant extract shows broad peak at 3467.77cm-1 - presence of OH group or carboxyl groups - after synthesis of AgNPs –shift at 3425.67cm-1 indicating the NH stretching - confirming the biofabrication of the nanoparticles - action of the phytochemicals

XRD pattern of Meliadubia SEM image of Meliadubia SEM analyze the shape of the silver nano particles - silver nano particles - spherical in shape – XRD analyze phasedistribution, crystallinity,purity of the synthesised nanoparticles particles. crystalline approximate spherical shape with size equivalent to 21.7nm with no impurities.

Aqueous Extract added and Zone of inhibition (mm/ml) Antibacterial Activity: PATHOGENS Aqueous Extract added and Zone of inhibition (mm/ml) 25 µl 50 µl 75 µl 100 µl Control Staphylococcus aureus 15 17 18 20 E.coli 22 Klebsiellapneumoniae 12 21 28 Vibrio cholera 25 CONCLUSION: AgNPs successfully obtained from bioreduction of silver nitrate solutions using Meliadubia leaf extract AgNPs characterized using UV-vis ,IR, SEM and XRD analysis Plant extract act as a reducing agent( Ag+ to Ag). The particles also exhibited good antimicrobial activity against K. pneumonia, S.aureus, V. choleraeand E.coli.Hence, due to their stable nature and antimicrobial property, these AgNPs may be well utilized in industrial and remedial purposes

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