Investigation of antibacterial properties silver nanoparticles prepared via green method

Chemistry Central Journal (Impact Factor: 1.66). 07/2012; 6(1):73. DOI: 10.1186/1752-153X-6-73
Source: PubMed

ABSTRACT Background
This study aims to investigate the influence of different stirring times on antibacterial activity of silver nanoparticles in polyethylene glycol (PEG) suspension. The silver nanoparticles (Ag-NPs) were prepared by green synthesis method using green agents, polyethylene glycol (PEG) under moderate temperature at different stirring times. Silver nitrate (AgNO3) was taken as the metal precursor while PEG was used as the solid support and polymeric stabilizer. The antibacterial activity of different sizes of nanosilver was investigated against Gram–positive [Staphylococcus aureus] and Gram–negative bacteria [Salmonella typhimurium SL1344] by the disk diffusion method using Müeller–Hinton Agar.

Formation of Ag-NPs was determined by UV–vis spectroscopy where surface plasmon absorption maxima can be observed at 412–437 nm from the UV–vis spectrum. The synthesized nanoparticles were also characterized by X-ray diffraction (XRD). The peaks in the XRD pattern confirmed that the Ag-NPs possessed a face-centered cubic and peaks of contaminated crystalline phases were unable to be located. Transmission electron microscopy (TEM) revealed that Ag-NPs synthesized were in spherical shape. The optimum stirring time to synthesize smallest particle size was 6 hours with mean diameter of 11.23 nm. Zeta potential results indicate that the stability of the Ag-NPs is increases at the 6 h stirring time of reaction. The Fourier transform infrared (FT-IR) spectrum suggested the complexation present between PEG and Ag-NPs. The Ag-NPs in PEG were effective against all bacteria tested. Higher antibacterial activity was observed for Ag-NPs with smaller size. These suggest that Ag-NPs can be employed as an effective bacteria inhibitor and can be applied in medical field.

Ag-NPs were successfully synthesized in PEG suspension under moderate temperature at different stirring times. The study clearly showed that the Ag-NPs with different stirring times exhibit inhibition towards the tested gram-positive and gram-negative bacteria.

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    • "In the present the study, T. involucrata silver nanoparticle exhibited by significant antibacterial activity against Streptococcus and Pseudomonas. The exact mechanism which silver nanoparticles employ to cause antimicrobial effect is not clearly known (Shameli et al., 2012). Silver nanoparticles have the ability to anchor to the bacterial cell wall and subsequently penetrate it, thereby causing structural changes in the cell membrane like the permeability of the cell membrane and death of the cell. "
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    ABSTRACT: The biosynthesis of silver nanoparticles is a cost effective and environmental friendly alternative to chemical and physical methods. In the present study, we have studied the green synthesis of silver nanoparticles from T. involucrata leaf extract and their biological properties. Silver nano particles (AgNPs) were characterized using UV-Visible spectrophotometer (UV-VIS), scanning electron microscope, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR). The AgNPs were tested for cytotoxic, antiangiogenic, antimicrobial as well as DNA diffusion assays. These biogenic nanoparticles showed significant cytotoxic activity against MOLT-4 cell lines, antiangiogenic and antimicrobial activity. Diffusion of DNA was comparatively higher in AgNPs treated cells than the control. Hence, T. involucrata leaf extract mediated AgNPs can be exploited in the development of novel drug. The unique properties of this AgNPs can be put to great use for human betterment.
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    • "Owing to the wide range of applications offered by nanoparticles in various fields, different approaches have been deliberated for their synthesis. Several methodologies were developed to obtain Ag NPs of wide ranging surface morphology including, biosynthesis (Vankar and Shukla 2012; Christensen et al. 2011, Shanmugavadivu et al. 2014), microwave processing (Pal et al. 2013), laser ablation (Amendola et al. 2012), gamma irradiation (Gasaymeh et al. 2010), electron irradiation (Misra et al. 2013), electrodeposition (Khaydarov et al. 2008; Sanchez et al. 2000; Roldan et al. 2013), green synthesis (Shameli et al. 2012; Pandey et al. 2012; Ahmad and Sharma 2012), sonoelectrochemical synthesis (Socol et al. 2002); chemical reduction (Sileikaite et al. 2009), photochemical method (Kutsenko and Granchak 2009), thermal decomposition, radiolytic reduction (Saion et al. 2013) etc., Among these techniques, bottom-up methods are frequently adopted for the synthesis of Ag NPs, since they offer easy and expedient route for the synthesis of Ag NPs. Among them electrochemical method is the most popular and frequently used method for the Ag NPs synthesis. "
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    ABSTRACT: This work exemplifies a simple and rapid method for the synthesis of silver nanodendrite with a novel electrochemical technique. The antibacterial activity of these silver nanoparticles (Ag NPs) against pathogenic bacteria was investigated along with the routine study of optical and spectral characterisation. The optical properties of the silver nanoparticles were characterised by diffuse reflectance spectroscopy. The optical band gap energy of the electrodeposited Ag NPs was determined from the diffuse reflectance using Kubelka–Munk formula. X-ray diffraction (XRD) studies were carried out to determine the crystalline nature of the silver nanoparticles which confirmed the formation of silver nanocrystals. The XRD pattern revealed that the electrodeposited Ag NPs were in the cubic geometry with dendrite preponderance. The average particle size and the peak broadening were deliberated using Debye–Scherrer equation and lattice strain due to the peak broadening was studied using Williamson–Hall method. Surface morphology of the Ag NPs was characterised by high-resolution scanning electron microscope and the results showed the high degree of aggregation in the particles. The antibacterial activity of the Ag NPs was evaluated and showed unprecedented level antibacterial activity against multidrug resistant strains such as Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumonia and Escherichia coli in combination with Streptomycin.
    01/2015; DOI:10.1007/s13204-014-0396-0
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    • "The synthesis of polymer nanocomposite is a basic visible feature of polymer nanotechnology [6] [7] [8] [9] [10] [11] [12]. Nanocomposites are two phase components where one of the phases is at least one dimension in 1 to 100 nanometer [13] [14] [15] [16] [17] [18] [19] [20] [21]. Nanocomposites have higher thermal and mechanical properties in comparison with other composites and also they have better recyclability and low weight [22] [23]. "
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    ABSTRACT: The goal of this study was to investigate the effect of modified rice straw (ORS) on the mechanical and thermal properties of modified rice straw/polycaprolactone composites (ORS/PCL-Cs). The composites (Cs) of polycaprolactone (PCL) with ORS were successfully synthesized using the solution-casting method. The RS modified with octadecylamine (ODA) as an organic modifier. The prepared composites were characterized by using powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier transforms infrared spectroscopy (FT-IR), and mechanical properties were investigated. Composites of ORS/PCL showed superior mechanical properties due to greater compatibility of ORS with PCL. The XRD results showed that the intensity of the peaks decreased with the increase of ORS content from 1.0 to 7.0 wt.% in comparison with PCL peaks. Tensile measurement showed an increase in tensile modulus but a decrease in tensile strength and elongation at break as the ORS contents are increased from 1.0 to 7.0 wt.%; on the other hand, tensile strength was improved with the addition of 5.0 wt.% of ORS. Thermal stability was decreased with the increase of ORS contents. SEM micrograph indicated good dispersion of ORS into the matrix, and FT-IR spectroscopy showed that the interaction between PCL and ORS is physical interaction.
    Journal of Nanomaterials 06/2014; 2014(7). DOI:10.1155/2014/675258 · 1.61 Impact Factor
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