ABSTRACT
Antibacterial activity of biosynthesized silver
nanoparticles (AgNPs) was significant in therapeutic application of nanotechnology.
These researchers studied an ecofriendly and rapid method for the first time to
synthesize silver nanoparticles using Zizyphus spina christi L aqueous
leaves extract (ZSE), and their antibacterial properties. The extract was found
to have the potential to form silver nanoparticles at room temperature within
few minutes. The green synthesized silver nanoparticles were characterized using
different techniques. The UV-visible spectrum of the solution containing AgNPs
showed a peak at 414 nm corresponding to the plasmon absorbance of silver
nanoparticles. The transmission electron microscopy (TEM) showed that the
formed particles were hexagonal in shape with appreciable Nano size ranging
from 21.5 to 59.67 nm. Fourier Transform Infrared Spectroscopy analysis (FTIR)
of biosynthesized AgNPs affirmed the role of ZSE as reducing and capping agent
of Ag+ ions to AgNPs, and X-Ray Diffraction patterns (XRD) showed
that they could be indexed as face-centered-cubic structure of silver.
Antibacterial activity of AgNPs was determined by well diffusion and micro
plate assay methods, showing maximum inhibition zones of 24 mm, 23 mm, 15 mm
and 17 mm against Staphylococcus aureus, Acinetobacter sp., Pseudomonas
aeruginosa and Escherichia coli respectively. The minimum inhibitory
concentration (MIC) and the minimum bactericidal concentration (MBC) results
showed that AgNPs had MIC, MBC of 45, 57 μg/mL, 49, 61 μg/mL, 63, 90 μg/mL and 59, 82 μg/mL against S. aureus, Acinetobacter sp., P. aeruginosa and E. coli respectively. Furthermore, the green
synthesized AgNPs were loaded on band-aids and screened for antibacterial
activity. The AgNPs loaded on band-aids exhibited strong antibacterial effect
against multi drug resistant bacteria. These nanoparticles could be used for treating
wounds and preparing wound dressing. Such researches are crucial in the
demonstration of therapeutic importance of silver nanoparticles in medical
application.