A comparative study of the antibacterial mechanisms of silver ion and silver nanoparticles by Fourier transform infrared spectroscopy

Objective: The present study was to synthesize nanoparticles using Manilkara hexandra stem bark extract its characterization and evaluating it by an antimicrobial and antioxidant assay. Methods: Manilkara hexandra stem bark silver nanoparticles (MHSB-AgNPs) was done by mixing silver nitrate (1 mmol) and aqueous stem bark extract and it was analyzed by UV-Visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), Zeta potential, Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDAX), Thermogravimetry/Differential Thermal Analysis (TG/DTA) and Differential scanning calorimetry (DSC). The antibacterial assay was done by a well diffusion method and also examined for antifungal assay was done by disk diffusion method and antioxidant potential Diphenyl-1-picryl hydrazyl (DPPH method) Results: Manilkara hexandra stem bark silver nanoparticles (MHSB-AgNPs) is characterized by various techniques such as UV-visible absorption spectrum ranges from 430 nm to 440 nm indicate silver nanoparticles. The Fourier Transform Infrared Spectroscopy consists of biomolecules acts as capping agent to form silver nanoparticles. Field Emission Scanning Electron Microscopy shows particle size ranges from 15 nm to 50 nm. Energy Dispersive Spectroscopy shows the presence of Silver. X-ray Diffraction corresponds to face-centered lattice planes (111), (200), (220) and (311). Dynamic Light Scattering show the range of 68 nm and Zeta potential show the negative value of-17 nm which has high stability. Silver nanoparticles is also examined by Thermogravimetry/Differential Thermal Analysis (TG/DTA) and Differential scanning calorimetry (DSC) this project the thermal stability of the nanoparticles. The aqueous stem bark is also examined by UV-visible absorption spectrum, Fourier Transform Infrared Spectroscopy (FTIR), and Gas Chromatography-Mass Spectrometry (GCMS). In GCMS 20 compounds were identified. Silver nanoparticles show high zone of inhibition in antimicrobial assays and act as a good antioxidant agent. Conclusion: It is eco-friendly, non-toxic, and it’s easy to synthesis and it shows good result in an antimicrobial and antioxidant assay can be applied in a pharmaceutical application.

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Extracellular Biofabrication, Characterization, and Antimicrobial Efficacy of Silver Nanoparticles Loaded on Cotton Fabrics Using Newly IsolatedStreptomycessp. SSHH-1E

Journal of Nanomaterials ◽

10.1155/2016/3257359 ◽

2016 ◽

Vol 2016 ◽

pp. 1-17 ◽

Cited By ~ 13

Author(s):

Noura El-Ahmady El-Naggar ◽

Attiya Mohamedin ◽

Sarah Shawqi Hamza ◽

Abdel-Dayem Sherief

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Silver Nanoparticles ◽

Fourier Transform ◽

Infrared Spectroscopy ◽

Fourier Transform Infrared Spectroscopy ◽

Fourier Transform Infrared ◽

Cell Free Supernatant ◽

Transmission Electron ◽

Vis Spectroscopy

Biological method for silver nanoparticles synthesis has been developed to obtain cost effective, clean, nontoxic, and ecofriendly size-controlled nanoparticles. The objective of this study is extracellular biosynthesis of antimicrobial AgNPs using cell-free supernatant of a localStreptomycessp. strain SSHH-1E. Different medium composition and fermentation conditions were screened for maximal AgNPs biosynthesis using Plackett-Burman experimental design and the variables with statistically significant effects were selected to study their combined effects and to find out the optimum values using a Box-Behnken design. The synthesized AgNPs were characterized using UV-visible spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy. Rapid biosynthesis of AgNPs was achieved by addition of 1 mM AgNO3solution to the cell-free supernatant. The produced particles showed a single surface plasmon resonance peak at 400 nm by UV-Vis spectroscopy which confirmed the presence of AgNPs.Streptomycessp. SSHH-1E was identified asStreptomyces narbonensisSSHH-1E. Transmission electron microscopy study indicated that the shape of AgNPs is spherical and the size is ranging from 20 to 40 nm. Fourier transform infrared spectroscopy analysis provides evidence for proteins as possible reducing and capping agents. Furthermore, the biosynthesized AgNPs significantly inhibited the growth of medically important pathogenic Gram-positive and Gram-negative bacteria and yeast. The maximum biosynthesis of AgNPs was achieved at initial pH of 8, peptone of 0.5 g, and inoculum age of 48 h. The statistical optimization resulted in a 4.5-fold increase in the production of AgNPs byStreptomyces narbonensisSSHH-1E.

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