scholarly journals Phytochemical Synthesis and Preliminary Characterization of Silver Nanoparticles Using Hesperidin

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Anish Stephen ◽  
Sankar Seethalakshmi
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Reaction Time ◽  
Silver Nanoparticle ◽  
Size Range ◽  
Transmission Electron ◽  
Vis Spectroscopy

This paper is the first of its kind for development of rapid and ecofriendly method for synthesis of silver nanoparticles from aqueous solution of silver nitrate using the flavonoid “hesperidin” and optimization of the methodology. There is formation of stable spherical silver nanoparticles in the size range of 20–40 nm. Optimization of methodology in terms of concentration of reactants and pH of the reaction mixture reduced the reaction time for silver nanoparticle formation to 2 mins. Silver nanoparticles (AgNPs) were characterized by UV-Vis spectroscopy and transmission electron microscopy (TEM). UV-vis spectroscopy derived spectrum demonstrated a peak of 430 nm which corresponds to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy revealed spherical shaped silver nanoparticles in the size range of 20–40 nm.

The Aggregation Study and Characterization of Silver Nanoparticles

2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Absorption Spectrum ◽  
Average Particle Size ◽  
Average Particle ◽  
Transmission Electron ◽  
Vis Spectroscopy

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.

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

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
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.

scholarly journals One pot synthesis of silver nanoparticles using a cyclodextrin containing polymer as reductant and stabilizer

2014 ◽  
Vol 5 ◽  
pp. 380-385 ◽  
Author(s):  
Arkadius Maciollek ◽  
Helmut Ritter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Optical Properties ◽  
Silver Nitrate ◽  
Room Temperature ◽  
One Pot ◽  
One Pot Synthesis ◽  
Transmission Electron ◽  
Vis Spectroscopy

A facile and one pot synthesis of silver nanoparticles with narrow size distributions using silver nitrate and a copolymer 1 from N-isopropylacrylamide (NIPAM) and mono-(1H-triazolylmethyl)-2-methylacryl-β-cyclodextrin acting as reductant and stabilizer without using any additional reducing agent is reported. The reduction was carried out in aqueous solution under pH neutral conditions at room temperature. The results of dynamic light scattering analysis and transmission electron microscopy show adjustable particle sizes from 30–100 nm, due to variation of silver nitrate concentration, the polymeric reducing and stabilisation agent concentration or reaction time. The spherical structure of the silver nanoparticles has been confirmed by UV–vis spectroscopy and transmission electron microscopy. The optical properties of the nanoparticles have also been characterized by fluorescence spectroscopy. The formed spherical particles are stable in aqueous medium at room temperature over a period of several weeks. Furthermore the changes in the optical properties of the nanoparticles due to thermo induced volume phase transition behavior of the thermoresponsive cyclodextrin containing polymer 1 have been characterized by UV–vis spectroscopy.

scholarly journals The morphology of silver nanoparticles prepared by enzyme-induced reduction

2012 ◽  
Vol 3 ◽  
pp. 404-414 ◽  
Author(s):  
Henrik Schneidewind ◽  
Thomas Schüler ◽  
Katharina K Strelau ◽  
Karina Weber ◽  
Dana Cialla ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Chemical Composition ◽  
Cross Sections ◽  
Silver Nanoparticle ◽  
Spherical Particles ◽  
Initial Growth ◽  
Nanoparticle Films ◽  
Transmission Electron

Silver nanoparticles were synthesized by an enzyme-induced growth process on solid substrates. In order to customize the enzymatically grown nanoparticles (EGNP) for analytical applications in biomolecular research, a detailed study was carried out concerning the time evolution of the formation of the silver nanoparticles, their morphology, and their chemical composition. Therefore, silver-nanoparticle films of different densities were investigated by using scanning as well as transmission electron microscopy to examine their structure. Cross sections of silver nanoparticles, prepared for analysis by transmission electron microscopy were additionally studied by energy-dispersive X-ray spectroscopy in order to probe their chemical composition. The surface coverage of substrates with silver nanoparticles and the maximum particle height were determined by Rutherford backscattering spectroscopy. Variations in the silver-nanoparticle films depending on the conditions during synthesis were observed. After an initial growth state the silver nanoparticles exhibit the so-called desert-rose or nanoflower-like structure. This complex nanoparticle structure is in clear contrast to the auto-catalytically grown spherical particles, which maintain their overall geometrical appearance while increasing their diameter. It is shown, that the desert-rose-like silver nanoparticles consist of single-crystalline plates of pure silver. The surface-enhanced Raman spectroscopic (SERS) activity of the EGNP structures is promising due to the exceptionally rough surface structure of the silver nanoparticles. SERS measurements of the vitamin riboflavin incubated on the silver nanoparticles are shown as an exemplary application for quantitative analysis.

scholarly journals Stachybotrys chartarum: A Novel Biological Agent for The Extracellular Synthesis of Silver Nanoparticles and Their Antimicrobial Activity

2015 ◽  
Vol 18 (2) ◽  
pp. 75 ◽  
Author(s):  
Abdel Ghany Tarek Mohamed
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Stachybotrys Chartarum ◽  
Capping Agent ◽  
Extracellular Synthesis ◽  
Transmission Electron

Microbial assisted biosynthesis of nanoparticles is a rapidly progressing area of nanobiotechnology. Inthis paper Stachybotrys chartarum assisted extracellular synthesis of silver nanoparticles (AgNPs) is reportedwhen challenged with 1mM silver nitrate (AgNO3). The characterization of AgNPs was carried out visualobservation and UV-Vis spectrophotometry. Further analysis carried out by Fourier Transform InfraredSpectroscopy (FTIR), provides evidence for the presence of proteins as capping agent, which helps in increasingthe stability of the synthesized AgNPs. Transmission Electron Microscopy (TEM) investigations confi rmedthat AgNPs were formed. The synthesized silver nanoparticles were found in the range of 65-108 nm. Finally,the antimicrobial susceptibility of AgNPs synthesized was investigated which exhibited more potent activityagainst bacteria than fungi compared with using silver nitrate at concentration 1mM. Keywords: Antimicrobial activity, Stachybotrys chartarum, Silver nanoparticles

scholarly journals Morphological characterization of fullerene–androsterone conjugates

2014 ◽  
Vol 5 ◽  
pp. 374-379 ◽  
Author(s):  
Alberto Ruiz ◽  
Margarita Suárez ◽  
Nazario Martin ◽  
Fernando Albericio ◽  
Hortensia Rodríguez
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Transmission Electron Microscopy ◽  
Morphological Characterization ◽  
The Self ◽  
Self Organization ◽  
Fullerene Derivatives ◽  
Transmission Electron ◽  
Scale Structures

Here we report on the self-organization characteristics in water of two diastereomer pairs of fullerene–androsterone hybrids that have the hydrophobic C60 appendage in the A and D ring of the androsterone moiety, respectively. The morphology and particle size in aqueous solution were determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS), with satisfactory agreement between both techniques. In general, these fullerene derivatives are shown to organize into spherical nano-scale structures with diameters in the ranges of 10–20 and 30–50 nm, respectively.

scholarly journals BIOSYNTHESIS AND CHARACTERIZATION OF SILVER NANOPARTICLES FROM MANGROVE BARK – RHIZOPHORA MUCRONATA EXTRACT

2020 ◽  
pp. 91-94
Author(s):  
AJI JOVITHA AT ◽  
DEIVASIGAMANI B
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
High Resolution ◽  
Room Temperature ◽  
Energy Dispersive ◽  
Rhizophora Mucronata ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy

Objective: The present study attempted to synthesize AgNPs from mangrove bark Rhizophora mucronata and analyze characteristics. The synthesized AgNPs analyzed with UV–vis spectroscopy, high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray (EDX) for confirming the nanoparticles. Methods: The dried R. mucronata bark was powdered and kept in at 55°C for 15 min in a water bath and cooled at room temperature to get the extract. The R. mucronata bark extract was treated with silver nitrate and kept overnight in the dark environment which will turn the solution to dark brown color. The silver nanoparticles were characterized using UV–visible absorption at room temperature. Further characterization was also done with X-ray diffraction, high-resolution transmission electron microscope measurements, and DLS analysis. Results: The synthesized AgNPs were analyzed with various analytical methods that revealed the abundant presence of silver nanoparticles. The UV–vis spectroscopy analysis exposed the surface plasmon resonance peak of 422 nm. High-resolution transmission electron microscopy (HRTEM) analysis indicated the size ranging from 10 nm to 200 nm in diameter and a spherical shaped poly dispersal of the particles. The energy-dispersive X-ray (EDX) and DLS also confirmed the presence of silver atoms. Conclusion: Silver nanoparticles of Rhizophora mucronata bark revealed a well-defined structure and may be used in antimicrobial function in further researches.

scholarly journals SYNTHESIS AND CATALYTIC ACTIVITY OF BRANCHED GOLD NANOPARTICLES IN AQUEOUS MEDIUM

2018 ◽  
Vol 55 (5B) ◽  
pp. 227
Author(s):  
Phan Ha Nu Diem
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Kinetic Data ◽  
Gold Nanostructures ◽  
Simple Method ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Experimental Parameters

In this article, a simple method for the preparation of multi–branched gold nanoparticles from an aqueous solution of silver seeds, cetyl-trimethylammonium bromide (CTAB), HAuCl4, and Pluronic F–127 was described. It was found that morphologies and sizes of gold nanostructures (AuNPs) depended strongly on such experimental parameters as concentrations of Pluronic F–127 and Au3+. The products were characterized by transmission electron microscopy (TEM). Interestingly, the multi – branched AuNPs were found to serve as an effective catalyst for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of NaBH4. Kinetic data have been obtained from monitoring the concentrations of 4-NP and BH4‒ by UV‒vis spectroscopy.

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