IOSR Journal of Pharmacy and Biological Sciences (IOSR-JPBS)
Polygonum glabrum Willd. leaf extract mediated green synthesis
of silver nanoparticles and their assessment of antimicrobial
activity
V. K. Rokhade and T.C.Taranath*
P.G.Department of studies in Botany, Environmental Biology Laboratory, Karnatak University, Dharwad-
580003, Karnataka, India.
*Corresponding Author: V. K. Rokhade
Abstract: Green nanotechnology is gaining importance due to the elimination of harmful reagents and
provides effective synthesis of expected products in an economically manner. In the present investigation
aqueous leaf extract of Polygonum glabrum Willd. was used for the synthesis of silver nanoparticles. The colour
of reaction mixture was changes from colouless to brown colour indicates the formation of silver nanoparticles,
further confirmed by characteristic UV-Vis absorption peak at 429 nm. Synthesized nanoparticles were
characterized by FTIR, Fluorescence Spectroscopy and SEM. Fluorescence Spectroscopy is a powerful tool to
study the tertiary structure of proteins. FTIR data revels that biomolecules involved in the reduction and
capping of silver nanoparticles. The SEM result shows the size of nanoparticles ranges from 10 to 35 nm and
are spherical in shape. XRD data showed that crystalline nature of nanosilver. The biogenic silver
nanoparticles showed excellent antimicrobial activity against S. typhi, E. coli, P. aeruginosa and S.aureus.
Keywords: Silver nanoparticles, Polygonum glabrum Willd, FTIR, Antimicrobial activity
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Date of Submission: 20-05-2018 Date of acceptance: 04-06-2018
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I. Introduction
Nanotechnology is referred to the particular technological goal of precisely manipulating atoms
and molecules for fabrication of macroscale products, also now referred to as molecular
nanotechnology 1. Dimensions between approximately 1 and 100 nanometers are known as the
nanoscale. The synthesis of nanoparticles and their characterization is an emerging field of
nanotechnology since past two decades due to their wide applications in the fields of physics,
chemistry, biology and medicine. Unusual physical, chemical and biological properties can emerge in
materials at the nanoscale. These properties may differ in important ways from the properties of bulk
materials and single atoms or molecules. Although metal is a poor catalyst in bulk form, nanosized
particles can exhibit excellent catalytic activity due to their relative high surface area-to- volume ratio
and their interface-dominated properties, which significantly differ from those of the bulk material
2
. Controlled size and composition of nanoparticles are of fundamental interest since they provide solutions to
environmental and technological challenges in the areas of catalysis, solar energy conversion and
waste water treatment. More recently, nanoscale materials has been looked at with interest for
synthesis of advanced materials, energy storage devices, electronic and optical displays, chemical and
biosensors, drug delivery, optical spectroscopy including surface-enhanced raman scattering 3 ,
detection and diagonostic, antimicrobial, therapeutics 4,5,6,7, biomedicine, waste water treatment 8 , food
industry 9 , Antidiabetic 10, 11, Antiviral 12 , anticancer13, Anti-inflammatory 14 and antiplasmodial 15 .
Nanoparticles are synthesized by physical and chemical methods but these methods have
certain disadvantages due to involvement of toxic chemicals. A large amount of toxic chemicals are
produced during the synthesis of nanomaterials and these chemicals pose a serious threat to
environment. Thus, there is a need for safe, clean, nontoxic and environment-friendly method for the
synthesis of nanoparticles. Researchers in the field of nanoparticles have laid emphasis on biological
method for synthesis of nanoparticles by biomimetic approach. Bio-inspired synthesis of metal
nanoparticles can be considered as an emerging branch of green chemistry in which plant extract,
bacteria, fungi and algae have been used for the reduction of Ag + to Ag0. Recently, number of plants
and plant parts such as leaf, fruit, flower, tuber and rhizome extract were used for the synthesis of silver
and gold nanoparticles, further testing the efficacy of nanoparticles for antimicrobial activity Viz.
DOI: 10.9790/3008- g 68 |
IOSR Journal of Pharmacy and Biological Sciences (IOSR-JPBS)
Garcinia mangostana 16 , Dioscorea bulbifera 17 , Alternanthera sessilis 18 , Terminalia arjuna 19 ,
Phyllanthus maderaspatensis 20, Cansjera rheedii J. F. 21, Hemidesmus indicus 22 , Linum usitatissimum
L. 23, Dimocarpus longan 24, Convolvulus pluricaulis 25 , Lavandula intermedia 26 , Allophylus serratus 27 ,
Origanum Vulgare L. 28 , Bauhinia acuminate and Biophytum sensitivum 29. Polygonum glabrum Willd. is
an annual or perennial herb, which belongs to the family Polygonaceae (Figure 1). The leaf extract of P.
glabrum contains
DOI: 10.9790/3008- www.iosrjournals.or 69 |
