Silver nanoparticles were prepared by chemical
reduction method. Silver nitrate was taken as the metal precursor and
hydrazine hydrate as a reducing agent. The formation of the silver
nanoparticles was monitored using UV-Vis absorption spectroscopy.
The UV-Vis spectroscopy revealed the formation of silver
nanopartícles by exhibing the typical surface plasmon absorption
maxima at 418-420 nm from the UV–Vis spectrum. Comparison of
theoretical (Mie light scattering theory) and experimental results
showed that diameter of silver nanoparticles in colloidal solution is
about 60 nm. We have used energy-dispersive spectroscopy (EDX),
X-ray diffraction (XRD), transmission electron microscopy (TEM)
and, UV–Vis spectroscopy to characterize the nanoparticles obtained.
The energy-dispersive spectroscopy (EDX) of the nanoparticles
dispersion confirmed the presence of elemental silver signal no peaks
of other impurity were detected. The average size and morphology of
silver nanoparticles were determined by transmission electron
microscopy (TEM). TEM photographs indicate that the nanopowders
consist of well dispersed agglomerates of grains with a narrow size
distribution (40 and 60 nm), whereas the radius of the individual
particles are between 10 and 20 nm. The synthesized nanoparticles
have been structurally characterized by X-ray diffraction and
transmission high-energy electron diffraction (HEED). The peaks in
the XRD pattern are in good agreement with the standard values of
the face-centered-cubic form of metallic silver (ICCD-JCPDS card
no. 4-0787) and no peaks of other impurity crystalline phases were
detected. Additionally, the antibacterial activity of the nanopartículas
dispersion was measured by Kirby-Bauer method. The nanoparticles
of silver showed high antimicrobial and bactericidal activity against
gram positive bacteria such as Escherichia Coli, Pseudimonas
aureginosa and staphylococcus aureus which is a highly methicillin
resistant strain.