Akshay S. Kulkarni; Geeta Shirnalli; Ashok M. Sajjan; Nagaraj R. Banapurmath; Ashok S. Shettar; Kartik J. Uttarkar
Abstract
A solution technique was adopted to develop membranes in which chitosan-wrapped silver nanoparticles (CS-wrapped Ag nanoparticles) were incorporated in poly(vinyl alcohol) (PVA). The morphological studies and the chemical compositions of the prepared membranes were investigated using the characterization ...
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A solution technique was adopted to develop membranes in which chitosan-wrapped silver nanoparticles (CS-wrapped Ag nanoparticles) were incorporated in poly(vinyl alcohol) (PVA). The morphological studies and the chemical compositions of the prepared membranes were investigated using the characterization techniques like Infrared Spectroscopy, Differential scanning colorimetry, Wide Angle X-ray Diffraction, Thermogravimetric analysis and scanning electron microscopy. The effects of CS-wrapped Ag nanoparticles on membrane swelling were systematically studied to know the gas separation performance of the membranes. TGA showed increased thermal stability of Ag-nanoparticles incorporated PVA membranes nearly twice that of plane PVA membranes. Further, SEM revealed that CS-wrapped Ag nanoparticles incorporation into the PVA membrane matrix showed good compatibility and high swelling properties.
Pragati Jamdagni; Poonam Khatri; J. S. Rana
Abstract
The current study reports biogenic synthesis of silver nanoparticles from Elettaria cardamomum. Elettaria leaf extract was used as reducing and capping agent for nanoparticle synthesis from parent solution of silver nitrate. Nanoparticle suspension was characterized mainly using UV-Visible spectroscopy. ...
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The current study reports biogenic synthesis of silver nanoparticles from Elettaria cardamomum. Elettaria leaf extract was used as reducing and capping agent for nanoparticle synthesis from parent solution of silver nitrate. Nanoparticle suspension was characterized mainly using UV-Visible spectroscopy. Synthesis parameters namely, time, metal ion concentration, leaf extract quantity, reaction temperature and pH are well known to affect the final product of synthesis and hence, were varied to assess optimum conditions for synthesis. Nanoparticles synthesized at optimum conditions were washed and characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM). Nanoparticles obtained were in the size range of 5-80 nm (TEM), with an average particle size of 29.96 nm as calculated using Debye-Scherrer formula and average hydrodynamic diameter of 32.12 nm (DLS). FTIR implicates plausible role of protein part of leaf extract in nanoparticle synthesis and DLS confirms monodisperse nature of the suspension. Nanoparticle suspension was found to be stable after four months of storage at room temperature without the addition of any stabilizing agents. Silver nanoparticles exhibited excellent antifungal activity against various fungal phytopathogens with minimum inhibitory concentration as low as 8 µg/mL for Aspergillus niger, making them potential antifungal agents in the field of agriculture. Copyright © 2018 VBRI Press.
Rachna .; Baljeet S. Saharan .; Mahender S. Yadav .; Nisha Sharma .
Abstract
A simple and efficient synthesis of silver nanoparticles (AgNPs) is reported here using red Dianthus caryophyllus flower, acting both as reducing and capping agent. The resultant silver colloids were characterized using UV-visible spectrophotometer, X-ray Diffractometer (XRD) and Transmission electron ...
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A simple and efficient synthesis of silver nanoparticles (AgNPs) is reported here using red Dianthus caryophyllus flower, acting both as reducing and capping agent. The resultant silver colloids were characterized using UV-visible spectrophotometer, X-ray Diffractometer (XRD) and Transmission electron microscope (TEM). The surface absorption plasmon response and kinematics of reduction of silver ions were observed by UV-visible spectroscopy. The crystalline fcc structure of AgNPs was confirmed by its XRD pattern. Their morphological study was done with TEM, showing spherically shaped AgNPs in the range 10-20 nm. The antibacterial action was also studied using Agar well diffusion method against pathogenic bacteria cultures (Staphylococcus aureus, Bacillus cereus and Escherichia coli). AgNPs showed better antimicrobial activity against S. aureus culture. Copyright © 2018 VBRI Press.
Aftab H. Mondal; Mohammad T. Siddiqui; Kehkashan Siddiqui; Qazi M. Rizwanul Haque
Abstract
In the present work, biosynthesis of silver nanoparticles (AgNPs) using isolate of Shigella sp. AS8 culture supernatant as a reducing agent has been demonstrated. Synthesis of AgNPs was completed within 180 min of incubation at 35 °C under bright light condition. The biosynthesized nanoparticles ...
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In the present work, biosynthesis of silver nanoparticles (AgNPs) using isolate of Shigella sp. AS8 culture supernatant as a reducing agent has been demonstrated. Synthesis of AgNPs was completed within 180 min of incubation at 35 °C under bright light condition. The biosynthesized nanoparticles were characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Dynamic light scattering (DLS), Transmission electron microscopy (TEM), Field emission scanning electron microscopy (FE-SEM) equipped with energy dispersive X-ray (EDX) and Atomic force microscopy (AFM). The formation of brown color reaction product with strong UV-vis spectrum absorption maxima at 411 nm due to surface plasmon resonance (SPR) indicated the synthesis of AgNPs. FTIR spectrum confirmed association of supernatant protein molecules with synthesized nanoparticles. DLS, TEM, FE-SEM and AFM showed biosynthesized nanoparticles were spherical in shape with an average size of 20 nm. EDX data analysis reveals presence of metallic silver. While, XRD analysis revealed that synthesized particles were pure and crystalline in nature. Further, AgNPs were evaluated as an antibacterial agent against extended spectrum β-lactamase (ESBL) positive water-borne pathogens. The results of present study suggest that biosynthesized AgNPs can be used to combat ESBL producing multidrug resistant bacteria.
