عنوان مجله
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Russian Journal of Physical Chemistry A
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کلیدواژهها
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antibacterial activity, S. aureus, E. coli, core-shell nanocomposites, PPG, PEG
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چکیده
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Fe3O4 magnetic nanoparticles (MNPs) were prepared by co-precipitation method. The nanoparticles
were silica coated using TEOS, and then modified by the polymeric layers of polypropylene glycol
(PPG) and polyethylene glycol (PEG). Finally, the core-shell samples were decorated with Ag, Au, and Cu
nanoparticles. The products were characterized by vibrating sample magnetometry (VSM), TGA, SEM,
XRD, and FTIR methods. The antibacterial activity of the prepared samples was evaluated in inactivation of
E. coli and S. aureus microorganisms, representing the Gram-negative and Gram-positive species, respectively.
The effect of solid dosage, bacteria concentration and type of polymeric modifier on the antibacterial
activity was investigated. TEM images of the bacteria were recorded after the treatment time and according
to the observed changes in the cell wall, the mechanism of antibacterial action was discussed. The prepared
nanostructures showed high antibacterial activity against both Gram-negative and Gram-positive bacteria.
This was due to the leaching of metal ions which subsequently led to the lysis of bacteria. A theoretical investigation
was also done by studying the interaction of loaded metals with the nucleotide components of the
microorganism DNA, and the obtained results were used to explain the experimental data. Finally, based on
the observed inactivation curves, we explain the antibacterial behavior of the prepared nanostructures mathematically.
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