scholarly journals Investigation of the Larvicidal Potential of Silver Nanoparticles againstCulex quinquefasciatus: A Case of a Ubiquitous Weed as a Useful Bioresource

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Elijah T. Adesuji ◽  
Omolara O. Oluwaniyi ◽  
Haleemat I. Adegoke ◽  
Roshila Moodley ◽  
Ayomide H. Labulo ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Electron Microscope ◽  
Volume Ratio ◽  
Average Diameter ◽  
Environmentally Benign ◽  
X Ray ◽  
Transmission Electron ◽  
Aqueous Leaf Extract ◽  
Temperature Time ◽  
Filariasis Vector

Biosynthesized silver nanoparticles (AgNPs) usingCassia hirsutaaqueous leaf extract were reported in this study. The synthesis was optimized by measuring various parameters such as temperature, time, volume ratio, and concentration. The surface plasmon resonance at 440 nm for 30°C and 420 nm for both 50°C and 70°C measured using the UV-Vis spectrophotometer confirmed the formation of AgNPs synthesized usingC.hirsuta(CAgNPs). The functional groups responsible for the reduction and stabilization of the NPs were identified using Fourier Transform Infrared (FTIR). The morphology, size, and elemental composition of the NPs were obtained using scanning electron microscope (SEM), transmission electron microscope (TEM), and energy dispersive X-ray spectroscopy (EDX). X-ray diffractometer was used to identify the phases and crystallinity of CAgNPs. Crystalline spherical NPs with average diameter of 6.9 ± 0.1 nm were successfully synthesized. The thermal analysis of CAgNPs was observed from DSC-TGA. The larvicidal results against the different larva instar stage ofCulex quinquefasciatusgave LC50= 4.43 ppm and LC90= 8.37 ppm. This is the first study on the synthesis of AgNPs usingC.hirsutaand its application against lymphatic filariasis vector. Hence, it is suggested that theC.hirsutasynthesized AgNPs would be environmentally benign in biological control of mosquito.

scholarly journals Facile Synthesis of Template-Induced SnO2Nanotubes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Yang Liu ◽  
Yang Jiao ◽  
Fengyu Qu ◽  
Lihong Gong ◽  
Xiang Wu
Keyword(s):  
Electron Microscope ◽  
Large Scale ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Transmission Electron ◽  
Experimental Parameters ◽  
Mild Temperature ◽  
Temperature Time

Large scale SnO2nanotubes are successfully obtained by a facile hydrothermal method at a mild temperature. The morphologies and the microstructures of the as-synthesized SnO2products are characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). The average diameter of the nanotubes is about 100 nm. The phase and composition of the as-obtained products are investigated by X-ray diffraction (XRD). A series of comparison experiments were conducted by varying the experimental parameters, such as temperature, time, and the amount of the alkali, to study the formation mechanism of SnO2nanotubes.

Mythology Merges with Technology for Majestic Production of Silver Nanoparticles: Rudraksha Enabled

2012 ◽  
Vol 585 ◽  
pp. 144-148
Author(s):  
Poushpi Dwivedi ◽  
S.S. Narvi ◽  
R.P. Tewari
Keyword(s):  
Silver Nanoparticles ◽  
Vital Role ◽  
Environmentally Benign ◽  
Size Analysis ◽  
Visible Spectroscopy ◽  
Efficient Manner ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
Cost Efficient

In this nanoregime attempts to bring forth nanoparticles and nanomaterials are myriads, with there interesting and demanding applications in almost every field. Today the field of nanoscience has bloomed with the confluence of nanotechnology with material science, biology, biotechnology and medicine and the need for nanotechnology will only increase as miniaturization becomes extremely important in various arrays of life. Since time immemorial silver nanoparticles have been extensively used for hygienic and healing purposes, and even until most recently, it has indispensible vital role especially in the biomedical arena. Thus in an attempt to generate silver nanoparticles employing green, environmentally benign route, we have designed to converge mythology with technology, with the mystical production of silver nanoparticles, enabled by the blueberry beads of the plant Elaeocarpus granitrus Roxb., the Rudraksha. This non-degradable bead does not disintegrate, but retains the potentiality, even after unlimited production of silver nanoparticles, assisting infinite times. The extremely cost-efficient nanoparticles thus developed in a superiorly efficient manner were characterized through different techniques; like UV/visible spectroscopy, PL spectroscopy, transmission electron microscopy, energy dispersive X-ray analysis and nanoparticle size analysis.

scholarly journals Alginate-Mediated Synthesis of Hetero-Shaped Silver Nanoparticles and their Hydrogen Peroxide Sensing ability

2020 ◽  
Author(s):  
Sneha Bhagyaraj ◽  
Igor Krupa
Keyword(s):  
Hydrogen Peroxide ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Environmentally Benign ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
X Ray ◽  
Transmission Electron ◽  
Wide Range ◽  
Pollution Detection

Silver nanoparticles have been the focus of extensive research for many decades due to their unique physical, chemical and electrical properties. Introducing new environmentally benign methods for the synthesis of silver nanoparticles is of great interest in the research community. In this work we propose a new method for the simple synthesis of stable heterostructured biopolymer (sodium alginate)-capped silver nanoparticles (Ag-NPs) based on green chemistry.The as-prepared nanoparticles were characterized using the ultraviolet–visible (UV–Vis) absorption spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and Dynamic light scattering (DLS) techniques. The results showed that the as-prepared Ag-NPs have a heterostructured morphology with particle size in the range 30 ± 18 – 60 ± 25 nm, showing a zeta potential of -62 mV. The silver nanoparticle formation was confirmed from UV-Vis spectra showing 424 nm as maximum absorption. The particle size and crystallinity of the as- synthesized nanoparticles were analyzed using TEM and XRD measurements respectively. FTIR spectra confirmed the presence of alginate as capping agent to stabilize the nanoparticles. The Ag-NPs also showed excellent sensing capability, with a linear response to hydrogen peroxide spanning a wide range of concentrations from 10-1 – 10-7 M, which indicates their high potential for water treatment applications, such as pollution detection and nanofiltration composites.

Analysing the phytochemistry and anti-oxidant property of fabricated silver nanoparticles using Catharanthus roseus leaf extract

2021 ◽  
Vol 16 (12) ◽  
pp. 72-79
Author(s):  
A.K. Keshari ◽  
S. Saxena ◽  
G. Pal ◽  
V. Srivashtav ◽  
R. Srivastav
Keyword(s):  
Silver Nanoparticles ◽  
Electron Microscope ◽  
Catharanthus Roseus ◽  
Leaf Extract ◽  
Spherical Shape ◽  
Silver Ions ◽  
Antioxidant Property ◽  
X Ray ◽  
Morphological Studies ◽  
Aqueous Leaf Extract

A green rapid biogenic synthesis of silver nanoparticles (AgNPs) using Catharanthus roseus leaf extract was performed. Synthesized nanoparticles were characterized using UV-Visible, Fourier transform infra-red (FTIR) and X-ray diffraction (XRD). The reduction of silver ions to AgNPs using C. roseus extract was completed within 240 mins. The formation of AgNPs was confirmed by Surface Plasmon Resonance (SPR) at 442 nm using UV-Vis Spectrophotometer and it is characterized by XRD, Transmission electron microscope (TEM) and Scanning electron microscope (SEM). The morphological studies revealed the spherical shape of the particles with sizes ranging from 16-35 nm and Energy dispersive X-ray (EDX) spectrum confirmed the presence of silver along with other elements in the plants metabolite. The extracellular AgNPs synthesis by aqueous leaf extract demonstrates ultra-fast, simple and inexpensive method comparable to other methods. The antioxidant assay of the synthesized AgNPs indicated that they have a strong antioxidant property as compared to the control. Since these compounds are also safe to use and discharged into the environment, the green AgNPs could be considered as an innovative alternative approach for biomedical and nanoscience based industries.

scholarly journals Biosynthesis of Anisotropic Silver Nanoparticles byBhargavaea indicaand Their Synergistic Effect with Antibiotics against Pathogenic Microorganisms

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Priyanka Singh ◽  
Yeon Ju Kim ◽  
Hina Singh ◽  
Ramya Mathiyalagan ◽  
Chao Wang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Vibrio Parahaemolyticus ◽  
Size Range ◽  
Average Diameter ◽  
Pathogenic Microorganisms ◽  
X Ray Diffraction ◽  
X Ray ◽  
Extracellular Biosynthesis ◽  
Predominant Component ◽  
Transmission Electron

The strainBhargavaea indicaDC1 isolated from four-year-oldP. ginsengrhizospheric soil was used to perform rapid and extracellular biosynthesis of anisotropic silver nanoparticles. The ultraviolet-visible (UV-vis) spectra of the reaction mixture containing silver nanoparticles showed a peak at 460 nm, corresponding to the surface plasmon absorbance of silver nanoparticles. Field-emission transmission electron microscopy (FE-TEM) structural characterization revealed the nanobar, pentagon, spherical, icosahedron, hexagonal, truncated triangle, and triangular nanoparticles, with the size range from 30 to 100 nm. The energy-dispersive X-ray (EDX) analysis and elemental mapping results also confirmed that the silver was the predominant component of isolated nanoparticles. The X-ray diffraction (XRD) results correspond to the purity of silver nanoparticles and dynamic light scattering (DLS) result indicated that the average diameter of particles was 111.6 nm. In addition, enhancement in antimicrobial activity of commercial antibiotics was observed against various pathogenic microorganisms such asVibrio parahaemolyticus, Salmonella enterica, Staphylococcus aureus, Bacillus anthracis, Bacillus cereus, Escherichia coli, andCandida albicans.

The Effect of Alkaline Ratios of NaOH to NH3 on the Formation of Nanostructured Titania

2017 ◽  
Vol 886 ◽  
pp. 42-47 ◽  
Author(s):  
Indriana Kartini ◽  
Inna Yusnila Khairani ◽  
Chotimah ◽  
Salim Mustofa ◽  
Sri Juari Santosa ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Electron Microscope ◽  
Volume Ratio ◽  
Major Contributor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Anatase Titania ◽  
Nanoparticle Morphology ◽  
Nanostructured Titania

The effect of alkaline solvent of NaOH and NH3 in the synthesis of nanostructured titania (TiO2) has been studied. Powder of anatase titania as the precursor was mixed with various volume ratios of 10 M of NaOH and 15 M of NH3. The mixture was heated in Teflon-lined autoclave at 150 °C for 24 h. The as-synthesized TiO2 powders were then washed with 0.1 M HCl and calcined at 300 °C. The calcined samples were characterized using TEM (transmission electron microscope), and XRD (X-Ray diffraction). Raman spectroscopy was further used to determine the contributing crystalline phases for the synthesized TiO2. It is shown that varying the solvent ratios of NOH to NH3 resulted in nanotubes, nanosheets, and nanoparticle morphology of TiO2. The TEM images showed the formation of nanotube structure in alkaline ratio NaOH:NH3 of 1:0 and 3:1, with diameter of about 10 nm. At volume ratio of 1:1, the nanosheets and nanotubes both were formed and at volume ratio of NaOH:NH3 of 1:3, nanosheets contributed as its main morphology. While, at fully NH3 solvent, the nanospheres with anatase domain were produced. Raman spectra confirmed that the major contributor for hydrothermal synthesis employing less NaOH for volume ratio of NaOH:NH3 of 3:1 was predominantly anatase with slight presence of titanate. For volume ratio at higher NH3 the presence of titanate is not prominent, but the morphology has already changed into more nanosheet and then nanospheres. The crystallinity of TiO2 anatase crystalline phase was enhanced as more NH3 utilized.

scholarly journals Rare Earth Dy3+ Activated MgSrAl10O17 Phosphors for Luminescence

2021 ◽  
Vol 9 (4) ◽  
pp. 373-378
Keyword(s):  
Electron Microscope ◽  
Average Diameter ◽  
Combustion Method ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increase With Increase ◽  
Transmission Electron ◽  
Transmission Electron Microscope Study ◽  
Thermo Luminescence

MgSrAl10O17:xDy3+ nanophosphors were fabricated by combustion method for different concentrations (x = 0, 0.0005, 0.001, 0.005, 0.01 and 0.02 mol) of Dysprosium (Dy). The synthesized nanophosphors were characterized by XRD, SEM, TEM, FTIR, PL and TL. The XRD (X-ray diffraction) showed crystalline hexagonal structure with preferred orientation of (107) plane. SEM (Scanning electron microscope) result shows the formation of nanosheets in irregular shape. TEM (transmission electron microscope) study revealed the nanoparticles within average diameter size of 30 nm. The FTIR ( fourier transform infrared spectrum) shows absorption peaks in numerous regions. TL (thermo-luminescence) properties included TL glow curves and TL response for different concentrations of Dy after exposure of 700 Gy gamma rays. TL intensity was found to increase with increase in concentration of dopant Dy and was found to show best result for x=0.02. Further PL (photoluminescence) characterization ofMgSrAl10O17:0.02 Dy3+ phosphor exhibits two main emission peaks at 484 and 575 nm due to Dy3+ ion, when excited with 350 nm wavelength.

scholarly journals Biosynthesis of Silver Nanoparticles by Conyza canadensis and Their Antifungal Activity against Bipolaris maydis

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1443
Author(s):  
Yueming Yi ◽  
Changjin Wang ◽  
Xinxin Cheng ◽  
Kechuan Yi ◽  
Weidong Huang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Electron Microscope ◽  
Antifungal Activity ◽  
Plant Pathogens ◽  
Average Diameter ◽  
Inhibition Zone ◽  
X Ray Diffraction ◽  
Bipolaris Maydis ◽  
Transmission Electron ◽  
Solid Plate

Silver nanoparticles were biosynthesized from Conyzacanadensis leaf extract with the help of a microwave oven. The UV-vis spectrum showed the maximum absorption at 441 nm, corresponding to the surface plasmon resonance of silver nanoparticles. Transmission electron microscope and scanning electron microscope images showed that the synthesized silver nanoparticles were spherical or near-spherical with an average diameter of 43.9 nm. X-ray diffraction demonstrated nanoparticles with a single-phase cubic structure. As-synthesized silver nanoparticles displayed prominent antifungal activity against Bipolaris maydis. The colony inhibition rate reached 88.6% when the concentration of nanosilver colloid was 100 μL·mL−1 (v/v). At such a concentration, no colony formation was observed on the solid plate. The diameter of the inhibition zone was 13.20 ± 1.12 mm. These results lay the foundation for the comprehensive control of plant pathogens using an environmentally friendly approach.

X-ray microanalysis of thin specimens in the transmission electron microscope at voltages up to 1000 Kv.

1978 ◽  
Vol 36 (1) ◽  
pp. 540-541
Author(s):  
G. Cliff ◽  
M.J. Nasir ◽  
G.W. Lorimer ◽  
N. Ridley
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Weight Fraction ◽  
Present Series ◽  
Constant Independent ◽  
X Ray ◽  
Transmission Electron ◽  
Series Of Experiments ◽  
Image Position ◽  
X Ray Absorption

In a specimen which is transmission thin to 100 kV electrons - a sample in which X-ray absorption is so insignificant that it can be neglected and where fluorescence effects can generally be ignored (1,2) - a ratio of characteristic X-ray intensities, I1/I2 can be converted into a weight fraction ratio, C1/C2, using the equationwhere k12 is, at a given voltage, a constant independent of composition or thickness, k12 values can be determined experimentally from thin standards (3) or calculated (4,6). Both experimental and calculated k12 values have been obtained for K(11<Z>19),kα(Z>19) and some Lα radiation (3,6) at 100 kV. The object of the present series of experiments was to experimentally determine k12 values at voltages between 200 and 1000 kV and to compare these with calculated values.The experiments were carried out on an AEI-EM7 HVEM fitted with an energy dispersive X-ray detector.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

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