GREEN SYNTHESIS OF SILVER NANOPARTICLES USING JUSTICIA ADHATODA AND ITS ACTIVITY AGAINST SELECTED CLINICAL ISOLATES

O. S. Aysha* and M.Kalaivani 

ABSTRACT

Nanotechnology deals with the synthesis of nanoparticles using living organisms. Plant has been used for synthesis of metal nanoparticles. Most of the reported green synthesis method using plant took more than 1hour for the formation of colloidal silver. Plant use can also be suitable for large scale synthesis of nanoparticles. Justicia adhatoda is one of the important herbs comparising several medical properties. About ten samples of pus, fifteen samples of urine, ten samples of throat and ten samples of wound where suspected growth was appeared in two samples of pus(A4 and A7), three samples of urine(B8 and B11), one sample of throat(C4), two samples of wound(D5 and D7). Based on the morphological and biochemical characteristics the organisms were identified as Staphylococcus aureus (A4, B11), Enterococcus faecalis (B8, D7), Pseudomonas aeruginosa(A7,D5), Micrococcus luteus(C4). The plant J. adhatoda leaves were collected from Ramanathapuram (Dt). The washed leaves were shade dried for 7 days. The dried plant leaves were then ground into powder. The finely ground Justicia adhatoda powder(10g) material was mixed with 100 ml of distilled water and kept in boiling at 100o C for 20 minutes. It was filtered with help of whatmann no: 1 filter paper and then stored in room temperature. 1mM and 2mM silver nitrate were prepared. Reduction of Ag+ ions was monitored by measuring the uv- vis spectrum. Absorption spectra of silvernanoparticles formed in the reaction media has the absorbance peak at 434nm. SEM analysis was done. SEM image also showed spherical shaped nanoparticle that were formed with a diameter ranges 84nm. Xray diffraction studies confirmed crystalline nature of the silver nanoparticles. The crystallite domain size was calculated by using the width in the XRD peaks. The peak value showed 38.3o, 46.37o, 64.53o and 77.40o corresponding to (111), (200) and (31) respectively, when compared to the XRD spectrum in the standard. Biosynthesis of silver nanoparticles were studied for antimicrobial activity against selective human pathogenic bacteria by using standard zone of inhibition (ZOI) microbiology assay, with a well size of 5 mm diameter and 20 μl of samples. Reference drug l of 0.1mg/ml concentration was used as a control antibacterial agent. The silver nanoparticles synthesized showed inhibition zone against all the isolates like Staphylococcus aureus (A4, B11), Enterococcus faecalis (B8, D7), Pseudomonas aeruginosa(A7, D5), Micrococcus luteus(C4).

Keywords: Justicia adhatoda, Silver nanoparticles, XRD, Nanoparticles, SEM.