Nanosized Gadoliniumorthoferrite-based Electrochemical Sensor for the Determination of Dopamine

Nano LIFE ◽  
2021 ◽  
pp. 2150002
Author(s):  
Susmita Pramanik ◽  
Yogendra Kumar ◽  
Parimal Karmakar ◽  
Dipak Kumar Das
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Sensor ◽  
Graphite Powder ◽  
Differential Pulse ◽  
Ferrite Nanoparticles ◽  
Ferric Nitrate ◽  
Cubic Crystal ◽  
Transmission Electron

This work deals with the synthesis, characterization of gadolinium ferrite nanoparticles, and its use as an electrochemical sensor for detection of dopamine. For the synthesis of gadolinium ferrite nanoparticles (GdFeO3 NPs), the combustion technique was employed using gadolinium oxide and ferric nitrate as precursor materials with sugar and ethanolamine as fuel. The size, shape and morphology of nanomaterials were determined by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The crystallite size of synthesized nanoparticles was found to be in the range of 40–45[Formula: see text]nm with a cubic crystal system. The electrochemical sensor, GdFeO3 NPs@graphite paste (GdFeO3/GP), was prepared by using synthesized nanomaterials and graphite powder by mixing in mortar in 1:4 ratio. cyclic voltammetry (CV) and Differential pulse voltammetry (DPV) techniques were employed to assess the electrochemical properties of the developed sensor. The result indicated that the developed sensor possessed better sensing ability, where minimum detection limit of dopamine at GdFeO3/GP electrode was 700[Formula: see text]nM with linearity range from 5[Formula: see text][Formula: see text]M to 160[Formula: see text][Formula: see text]M.

Preparation of yolk–shell structured Ag@Cu particles and their application in high performance electrochemical sensing of p-aminobenzoic acid

2019 ◽  
Vol 97 (2) ◽  
pp. 140-146
Author(s):  
Tian Gan ◽  
Zhikai Wang ◽  
Mengru Chen ◽  
Wanqiu Fu ◽  
Haibo Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Performance ◽  
Electrochemical Impedance ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Electrochemical Sensing ◽  
High Catalytic Activity ◽  
Aminobenzoic Acid ◽  
Transmission Electron

In this work, the Ag@Cu particles with yolk–shell nanostructure was prepared by facile solvothermal method, which was modified on glassy carbon electrode (GCE) to fabricate electrochemical sensor for the convenient and fast determination of p-aminobenzoic acid (PABA). The surface morphology and electrochemical properties of the as-prepared Ag@Cu nanocomposite modified electrode were characterized by scanning electron microscopy, transmission electron microscopy, chronocoulometry, and electrochemical impedance spectroscopy. Further, the electrochemical sensing of PABA was performed on the Ag@Cu/GCE using cyclic voltammetry and differential pulse voltammetry techniques, showing high catalytic activity. Under the optimal conditions, the sensor exhibited a wide linear range, high sensitivity, and low detection limit of 0.315 μmol/L for PABA. The developed sensor was also successfully applied for PABA detection in anesthetic and cosmetics with satisfactory results.

Preparation and Characterization of Nanocrystalline Gadolinium Oxide Powders and Films

2020 ◽  
Vol 850 ◽  
pp. 267-272 ◽  
Author(s):  
Regina Burve ◽  
Vera Serga ◽  
Aija Krūmiņa ◽  
Raimons Poplausks
Keyword(s):  
Electron Microscopy ◽  
Single Phase ◽  
Gadolinium Oxide ◽  
X Ray Diffraction ◽  
Cubic Crystal ◽  
Glass Substrates ◽  
Oxide Powders ◽  
Transmission Electron ◽  
The Mean

Due to its magnetic, electrical, absorption, and emission properties, nanoscale gadolinium oxide is widely used in various fields. In this research, nanocrystalline Gd2O3 powders and films on glass substrates have been produced by the extraction-pyrolytic method. X-ray diffraction analysis revealed the formation of single phase Gd2O3 with cubic crystal structure and the mean crystallite size from 9 to 25 nm in all produced materials. The morphology of samples has been characterized by scanning electron microscopy and transmission electron microscopy.

Structure Determination of Clusters Formed in Ultra-Low Energy High-Dose Implanted Silicon

2005 ◽  
Vol 108-109 ◽  
pp. 303-308 ◽  
Author(s):  
N. Cherkashin ◽  
Martin J. Hÿtch ◽  
Fuccio Cristiano ◽  
A. Claverie
Keyword(s):  
Electron Microscopy ◽  
Geometric Phase ◽  
Low Energy ◽  
High Dose ◽  
Dislocation Loops ◽  
Weak Beam ◽  
Transmission Electron ◽  
Geometric Phase Analysis

In this work, we present a detailed structural characterization of the defects formed after 0.5 keV B+ implantation into Si to a dose of 1x1015 ions/cm2 and annealed at 650°C and 750°C during different times up to 160 s. The clusters were characterized by making use of Weak Beam and High Resolution Transmission Electron Microscopy (HRTEM) imaging. They are found to be platelets of several nanometer size with (001) habit plane. Conventional TEM procedure based on defect contrast behavior was applied to determine the directions of their Burger’s vectors. Geometric Phase Analysis of HRTEM images was used to measure the displacement field around these objects and, thus, to unambiguously determine their Burger’s vectors. Finally five types of dislocation loops lying on (001) plane are marked out: with ] 001 [1/3 ≅ b and b ∝ [1 0 1], [-1 0 1], [0 1 1], [0 -1 1].

scholarly journals 3D-Flower-Like Copper Sulfide Nanoflake-Decorated Carbon Nanofragments-Modified Glassy Carbon Electrodes for Simultaneous Electrocatalytic Sensing of Co-existing Hydroquinone and Catechol

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2289 ◽  
Author(s):  
Lina Abdullah Alshahrani ◽  
Liqiong Miao ◽  
Yanyu Zhang ◽  
Shengming Cheng ◽  
Palanivel Sathishkumar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Glassy Carbon ◽  
Photoelectron Spectroscopy ◽  
Copper Sulfide ◽  
Environmental Pollutants ◽  
Differential Pulse ◽  
Glassy Carbon Electrodes ◽  
X Ray ◽  
Transmission Electron

A copper sulfide nanoflakes-decorated carbon nanofragments-modified glassy carbon electrode (CuS-CNF/GCE) was fabricated for the electrocatalytic differentiation and determination of hydroquinone (HQ) and catechol (CC). The physicochemical properties of the CuS-CNF were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. The electrocatalytic determination of HQ and CC over the CuS-CNF/GCE was evaluated by cyclic voltammetry and differential pulse voltammetry. An excellent detection limit and sensitivity of the CuS-CNF/GCE are obtained (0.293 µM and 0.259 µM) with a sensitivity of 184 nA µM−1 cm−2 and 208 nA µM−1 cm−2 (S/N=3) for HQ and CC, respectively. In addition, the CuS-CNF/GCE shows a selective identification of HQ and CC over potential interfering metal ions (Zn2+, Na+, K+, NO3−, SO42−, Cl−) and organic compounds (ascorbic acid, glucose), and a satisfactory recovery is also obtained in the spiked water samples. These results suggest that the CuS-CNF/GCE can be used as an efficient electrochemical sensor for the simultaneous determination of co-existing environmental pollutants such as HQ and CC in water environments with high selectivity and acceptable reproducibility.

Characterization of the parameters relating adjacent grains using transmission electron microscopy

2010 ◽  
Vol 43 (6) ◽  
pp. 1495-1501 ◽  
Author(s):  
H. W. Jeong ◽  
S. M. Seo ◽  
H. U. Hong ◽  
Y. S. Yoo
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Coincident Site Lattice ◽  
Cubic Crystal ◽  
Kikuchi Pattern ◽  
Orthogonal Relationship ◽  
Transmission Electron ◽  
Angle Of Deviation ◽  
The Relationship

A simple technique is presented for characterizing parameters such as the misorientation angle and the axis of rotation between two adjacent grains using transmission electron microscopy (TEM), without the need for an image of the Kikuchi pattern. The technique described makes use of the orthogonal relationship between the tilt axes used in TEM and the axes of the cubic crystal. The relationship was established using the well known triangulation method, in which the direction of the crystal parallel to the beam direction is determined from the measured tilt angles of the three zone axes. The error in measuring the tilt angles of the three zone axes can be evaluated by comparing the measured and crystallographic angles. The angle of deviation from the coincident site lattice (CSL) that results from the measurement error could be reduced by establishing the modified orthogonal relationship between the tilt and crystal axes. The use of this method could provide accurate measurement in real time for indexing a CSL boundary using TEM.

Cryomicroscopy of low-Tg latex particles via freeze drying

1993 ◽  
Vol 51 ◽  
pp. 1198-1199
Author(s):  
J. R. Reffner
Keyword(s):  
Electron Microscopy ◽  
Freeze Drying ◽  
Room Temperature ◽  
Film Formation ◽  
Direct Determination ◽  
Particle Morphology ◽  
Latex Particles ◽  
Transmission Electron

Transmission Electron Microscopy (TEM) is a powerful tool for investigating the structure of latex particles. However, examining low Tg (glass transision, Tg < room temperature) latex particles requires special techniques due to the significant deformation which occurs if the particles are dispersed onto a substrate at room temperature. Here a freeze drying (FD) technique is presented which permits individual emulsion particles, including stained particles, to be examined in a manner that minimizes deformation by maintaining the particles at temperatures below Tg.Typically, particle morphology is determined from images of individual latex particles dispersed onto a supporting ultra-thin substrate or from images of ultra-microtomed sections of films cast from the latex. Examining particles dispersed onto a substrate is often advantageous, allowing direct determination of particle shape and characterization of the morphology prior to the film formation process. Although low Tg materials can be examined using this technique, information about the size, shape and morphology of phase separated domains can be obscured by the deformation which occurs when the particles are examined at room temperature.

Defect and Microstructural Analyses in Ferromagnetic Material

1985 ◽  
Vol 62 ◽  
Author(s):  
L. L. Horton
Keyword(s):  
Electron Microscopy ◽  
Magnetic Domain ◽  
Ferromagnetic Material ◽  
Ferromagnetic Materials ◽  
Dislocation Loops ◽  
Cavity Shape ◽  
Transmission Electron ◽  
Shape Analyses

ABSTRACTTransmission electron microscopy (TEM) of ferromagnetic materials requires special and often time-consuming procedures to obtain good images. Tilting and high resolution experiments are particularly difficult. A survey of several investigations of microstructures in ferromagnetic materials ranging from pure iron to commercial magnet materials is presented. The topics of these investigations include determination of Burgers vectors and interstitial/vacancy character for dislocation loops, cavity shape analyses, magnetic domain/microstructure correlations, and characterization of structures resulting from isotropic spinodal decomposition. Problems encountered during these studies as they relate to magnetic materials and the modifications to standard microscope operating procedures required to overcome these problems are presented. This discussion includes specimen requirements, specimen loading and insertion, and alignment corrections required during specimen tilting.

scholarly journals Characterization of the Morphology of Faceted Particles by Transmission Electron Microscopy

2001 ◽  
Vol 703 ◽  
Author(s):  
Shirley Turner ◽  
David S. Bright
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Sample Holder ◽  
Transmission Electron ◽  
Complete Determination ◽  
Faceted Particles ◽  
Microscopy Images

ABSTRACTFaceting in a polyhedral rutile particle was modeled from transmission electron microscopy images. A double-tilt, rotate transmission electron microscope (TEM) sample holder was used to manipulate the particle. Using this holder, it was possible to align the c axis of the particle along one of the axes of the sample holder. This alignment allowed images to be obtained of the particle in several orientations around its c axis. Comparison of dimensions and angles obtained to those obtained for hypothetical models of the particle gives information about its likely prismatic and pyramidal faceting. This approach to facet modeling is useful for more complete determination of the faceting in individual euhedral particles using transmission electron microscopy.

Cryomicroscopy of multiphase latices

1991 ◽  
Vol 49 ◽  
pp. 1060-1061
Author(s):  
O. L. Shaffer ◽  
M.S. El-Aasser ◽  
C. L. Zhao ◽  
M. A. Winnik ◽  
R. R. Shivers
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Freeze Fracture ◽  
Particle Morphology ◽  
Second Stage ◽  
Transmission Electron ◽  
Important Approach ◽  
Carbon Coated ◽  
Preparation Techniques

Transmission electron microscopy is an important approach to the characterization of the morphology of multiphase latices. Various sample preparation techniques have been applied to multiphase latices such as OsO4, RuO4 and CsOH stains to distinguish the polymer phases or domains. Radiation damage by an electron beam of latices imbedded in ice has also been used as a technique to study particle morphology. Further studies have been developed in the use of freeze-fracture and the effect of differential radiation damage at liquid nitrogen temperatures of the latex particles embedded in ice and not embedded.Two different series of two-stage latices were prepared with (1) a poly(methyl methacrylate) (PMMA) seed and poly(styrene) (PS) second stage; (2) a PS seed and PMMA second stage. Both series have varying amounts of second-stage monomer which was added to the seed latex semicontinuously. A drop of diluted latex was placed on a 200-mesh Formvar-carbon coated copper grid.

Applications of Transmission Electron Microscopy in the Characterization of Metal Machinability

1968 ◽  
Vol 26 ◽  
pp. 442-443 ◽  
Author(s):  
L.E. Murr ◽  
A.B. Draper
Keyword(s):  
Electron Microscopy ◽  
State Physics ◽  
Test Material ◽  
Milling Machine ◽  
Rotary Table ◽  
Solid State Physics ◽  
Materials Properties ◽  
Transmission Electron ◽  
Selection Of

The industrial characterization of the machinability of metals and alloys has always been a very arbitrarily defined property, subject to the selection of various reference or test materials; and the adoption of rather naive and misleading interpretations and standards. However, it seems reasonable to assume that with the present state of knowledge of materials properties, and the current theories of solid state physics, more basic guidelines for machinability characterization might be established on the basis of the residual machined microstructures. This approach was originally pursued by Draper; and our presentation here will simply reflect an exposition and extension of this research.The technique consists initially in the production of machined chips of a desired test material on a horizontal milling machine with the workpiece (specimen) mounted on a rotary table vice. A single cut of a specified depth is taken from the workpiece (0.25 in. wide) each at a new tool location.

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