Peroxidase Mimic Activities of Copper Selenide (CuSe) Nanoplates for Sensing H2O2 and L-Cysteine

2020 ◽  
Vol 20 (9) ◽  
pp. 5369-5375
Author(s):  
Bai Maojuan ◽  
Xu Chengcheng ◽  
Huang Xuanye ◽  
Liu Yanan ◽  
Wan Jun
Keyword(s):  
Electron Microscopy ◽  
Detection Limit ◽  
Energy Dispersive Spectrometer ◽  
Catalytic Efficiency ◽  
Relative Standard Error ◽  
Colorimetric Determination ◽  
Peroxidase Mimic ◽  
Biomedical Analysis ◽  
X Ray ◽  
Relative Standard

Compared with natural enzymes, artificial mimic enzymes have been widely studied for their high stability and cost effectiveness. In this study, CuSe nanoplates as a simulated enzyme which does not contain precious metals, has peroxidase activity. CuSe nanoplates were prepared and characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray energy dispersive spectrometer (EDS). Kinetic studies show that CuSe nanoplates exhibits a higher affinity for 3,3′,5,5′-teramethylbenzidine (TMB) than horseradish peroxidase (HRP). The rapid colorimetric determination of H2O2 and L-cysteine were developed based on the catalytic efficiency. The linear range of detection for H2O2 is 5.0×10−6~8.0×10−5 M, and the detection limit is 2.9×10−6 M, while the relative standard error is less than 5%. In addition, L-cysteine was detected with a detection limit of 0.2×10−6 M. The good selectivity of the determination to H2O2 and L-cysteine in aqueous solution was also achieved. CuSe nanoplates as a simulated enzyme for sensor applications would be used in environmental monitoring and biomedical analysis.

scholarly journals Polyarylene Ether Nitrile and Barium Titanate Nanocomposite Plasticized by Carboxylated Zinc Phthalocyanine Buffer

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 418 ◽  
Author(s):  
Shuning Liu ◽  
Chenchen Liu ◽  
Changyu Liu ◽  
Ling Tu ◽  
Yong You ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Barium Titanate ◽  
Photoelectron Spectroscopy ◽  
Energy Dispersive Spectrometer ◽  
Composite Films ◽  
Zinc Phthalocyanine ◽  
Hydroxyl Groups ◽  
X Ray ◽  
Polyarylene Ether Nitrile ◽  
High Dielectric

Barium titanate (BT) and polyarylene ether nitrile (PEN) nanocomposites with enhanced dielectric properties were obtained by using carboxylatedzinc phthalocyanine (ZnPc-COOH) buffer as the plasticizer. Carboxylated zinc phthalocyanine, prepared through hydrolyzing ZnPc in NaOH solution, reacted with the hydroxyl groups on the peripheral of hydrogen peroxide treated BT (BT-OH) yielding core-shell structured BT@ZnPc. Thermogravimetric analysis (TGA), transmission electron microscopy (TEM), TEM energy dispersive spectrometer mapping, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) demonstrated successful preparation of BT@ZnPc. The fabricated BT@ZnPc was incorporated into the PEN matrix through the solution casting method. Rheological measurements demonstrated that the ZnPc-COOH buffer can improve the compatibility between BT and PEN effectively. With the existence of the ZnPc-COOH buffer, the prepared BT@ZnPc/PEN nanocomposites exhibit a high dielectric constant of 5.94 and low dielectric loss (0.016 at 1000 Hz). BT@ZnPc/PEN dielectric composite films can be easily prepared, presenting great application prospects in the field of organic film capacitors.

Composition and Microstructure of a Natural Nano-Structure Mineral: Six-Ring Rock

2011 ◽  
Vol 295-297 ◽  
pp. 869-872
Author(s):  
Qing Shan Li ◽  
Xin Wang ◽  
Jun Liu ◽  
Guang Zhong Xing
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectrometer ◽  
The Body ◽  
X Ray Diffraction ◽  
Nano Structure ◽  
X Ray ◽  
Transmission Electron ◽  
Nano Size ◽  
Scanning Electron

Six-ring Rock is widely used as containers of water and additives to produce health care products. In this paper, the composition and microstructure of Six-ring Rock have been investigated by using scanning electron microscopy, energy dispersive spectrometer, transmission electron microscopy, x-ray diffraction and other technologies. Results show that Six-ring Rock is composed of CaMg(CO3)2, SiO2 and KAlSi3O8. Fe atoms exist in CaMg(CO3)2 by replacing Mg atoms. Six-ring Rock shows nano-size lamellar and acerose microstructures on the surface, and nano-size monocrystals in the body. Six-ring Rock is a natural nano structure mineral.

TEM Study of Rutile-Phase TiO2 Nanosheets

2013 ◽  
Vol 850-851 ◽  
pp. 156-159
Author(s):  
Xin Yan Wu ◽  
Wei Xiong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
Rutile Phase ◽  
High Photocatalytic Activity ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process

TiO2 nanosheets have been successfully synthesized via a simple sol-gel process. These nanostructures were characterized by transmission electron microscopy (TEM) and x-ray energy dispersive spectrometer (EDS). The sheet-shaped single-crystalline nanostructures are pure rutile-phase structure, with landscape dimension of 10-45 nm. EDS investigation confirms that the TiO2 nanosheets are only composed of Ti and O, and the atomic ration of Ti and O is close to 1:2. High photocatalytic activity might be expected for those TiO2 nanosheets due to their large surface area.

scholarly journals Improvement of Dispersibility of Graphene Oxide by Surface Modification with Rare Earths

2022 ◽  
Author(s):  
Yong Li ◽  
Zhou Jiang ◽  
Haidong Yu ◽  
Xuebin Zhou ◽  
Peng Yi
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Photoelectron Spectroscopy ◽  
Energy Dispersive Spectrometer ◽  
X Ray ◽  
Modified Graphene Oxide ◽  
Modified Graphene ◽  
The Rare Earth

Abstract Rare earth-modified graphene oxide (RE-M-GO) materials were successfully prepared by infiltration and heating modifier method. The morphology and phase structure of RE-M-GO were characterized by scanning electron microscopy(SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive spectrometer(EDS). The changes of the chemical structure were indicated by Fourier transform infrared (FTIR). X-ray photoelectron spectroscopy(XPS) was used to study the chemical state of the surface elements of graphene oxide which showed that the rare earth elements were added to the graphene oxide functional groups through the coordination reaction. Additionally, the findings concluded that the effect of modification by Ce is more obvious than La elements and the RE-M-GO materials prepared by the heating modifier method had better dispersibility than infiltration. With activating effect, the rare earth elements grafting to graphene oxide will contribute to its combination with other materials.

Fabrication of Novel Z-Scheme Bi2WO6/NaBiO3 Nanocomposites with Enhanced Photocatalytic Activity in the Degradation of 2,3-Dichlorophenol

2020 ◽  
Vol 20 (5) ◽  
pp. 3105-3116 ◽  
Author(s):  
Xin-Yue Gu ◽  
Qiu Wang ◽  
Da-Peng Zhang ◽  
Xin-Xiang Geng ◽  
Zhen-Xing Zha ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Energy Dispersive Spectrometer ◽  
Energy Levels ◽  
Degradation Process ◽  
Photoelectrochemical Performance ◽  
X Ray ◽  
Oxidative Species

The Z-scheme Bi2WO6/NaBiO3 nanocomposites were first fabricated by a facile hydrothermal method, and were then characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive spectrometer, Fourier-transform-infrared spectroscopy, X-ray photoelectron spectroscopy and N2 adsorption–desorption. The as-prepared Bi2WO6/NaBiO3 nanocomposites exhibit outstanding photocatalytic activity and recyclability. A 98.4% photodegradation of 2,3-dichlorophenol (50 mg·L−1) was attained in the presence of Bi2WO6/NaBiO3 (1:10) under the visible-light irradiation in 30 min. In particular, the photocatalytic mechanism has been discussed in detail, based on four aspects: (1) oxidative species, (2) photoelectrochemical performance, (3) conduction band and valence band energy levels and (4) possible transition states and reactions. In conclusion, O−2 is the main active oxidative species in the Bi2WO6/NaBiO3 nanocomposite. The material has higher photocurrent and visible light adsorption but lower electron–hole pairs recombination, which contributes to distinguished photocatalytic efficiency. The Z-scheme photocatalytic path was proposed and the possible degradation process and routes have been summarized.

Colorimetric Determination of Total Iodine in Foods by Iodide-Catalyzed Reduction of Ce+4

1986 ◽  
Vol 69 (4) ◽  
pp. 687-689 ◽  
Author(s):  
Peter W F Fischer ◽  
Mary R L’Abbé ◽  
Alexandre Giroux
Keyword(s):  
Detection Limit ◽  
Reference Material ◽  
Standard Reference Material ◽  
Dairy Products ◽  
Colorimetric Method ◽  
Colorimetric Determination ◽  
Acid Digestion ◽  
Total Iodine ◽  
Relative Standard

Abstract An earlier acid digestion determination of iodine in foods was modified to provide an improved detection limit and to allow for the analysis of a greater variety and larger amounts of foods. The organic material in the sample was oxidized overnight by concentrated nitric acid, followed by digestion in a mixture of concentrated sulfuric and 70% perchloric acid. The iodine was determined by an automated colorimetric method based on the iodide-catalyzed reduction of Ce+4 by As+3. The method had an average relative standard deviation of 3.1% for the samples analyzed, and a detection limit of 0.1 ng/mL in the digested solution and 5 ng/g in a 2 g sample prior to digestion. The recovery of added iodine ranged from 90.3 to 101.3%, using external standards. Samples analyzed included NBS Standard Reference Material 1549, and composites of a variety of dairy products, meat, eggs and fish, cereals, and potatoes. The iodine detected in these samples ranged from 9 ng/g for the potato group to 3360 ng/g for the standard reference material.

Preparation of Cerium Oxide Tubes with Wool Fibers as Template

2015 ◽  
Vol 671 ◽  
pp. 248-254
Author(s):  
Jia Li Gu ◽  
Li Jiang Lu ◽  
Song Liu ◽  
Min Shao ◽  
Guo Qing Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cerium Oxide ◽  
Vapor Deposition ◽  
Energy Dispersive Spectrometer ◽  
Deposition Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Wool Fibers ◽  
Scanning Electron

Using wool fibers as template and Ce (NO3)3•6H2O, PEG and NH3·H2O as precursors, micron-scale CeO2tubes composed of well-crystalline CeO2nanoparticles have been synthesized. Cerium oxide was first precipitated on the wool fibers by vapor deposition method, then the fibers were removed by a two-step calcination. The obtained products were characterized by scanning electron microscopy (SEM), thermogravimetric Analyzer (TGA), powder X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). The results show that intact tubes with a diameter of 8~12μm have been successfully prepared.

Effect of Nd Addition on Microstructure of Mg-Zn-Nd Master Alloys

2012 ◽  
Vol 500 ◽  
pp. 646-650 ◽  
Author(s):  
Zhen Wei Zhao ◽  
Xin Ying Teng ◽  
Guo Rong Zhou
Keyword(s):  
Electron Microscopy ◽  
Growth Process ◽  
Energy Dispersive Spectrometer ◽  
X Ray Diffraction ◽  
Growth Morphology ◽  
X Ray ◽  
Nd Addition ◽  
Master Alloys ◽  
The Matrix ◽  
Scanning Electron

Mg-Zn-Nd master alloys containing spherical quasicrystal phase were prepared under conventional casting conditions. The microstructures and phases of Mg-Zn-Nd ternary alloy have been investigated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). The results show that the microstructure of Mg-Zn-Nd master alloys has been changed significantly with the addition of Nd. When adding 5wt% Nd, it is clear that a lot of spherical I-phase with high roundness and size below 10μm distributed evenly in the matrix. With the increase of Nd, the number of spherical I-phases is reduced and rod-like phases increased. The growth process and the final growth morphology of quasicrystal phase are restricted by the element Nd, thus the growth rates of all quasicrystal growth surfaces tend to be consistent, which contributes to the formation of spherical quasicrystal phase.

Optical and Electron Microscopy Investigation of Damaged Storz Firehose Couplings Microstructure

2018 ◽  
Vol 919 ◽  
pp. 379-385
Author(s):  
Cornel Băbuţ ◽  
Nicolae Ungureanu ◽  
Gheorghe Iepure
Keyword(s):  
Electron Microscopy ◽  
Energy Dispersive Spectrometer ◽  
Failure Mechanisms ◽  
Nucleation And Growth ◽  
Microscopic Investigation ◽  
X Ray ◽  
Micro Cracks ◽  
Microscopy Investigation ◽  
Electron Microscopy Investigation ◽  
Microstructural Defects

This paper presents the results of a microscopic investigation of fractured Storz type fire hose couplings. It is part of the authors’ previous investigations on the failure mechanisms of this type of couplings. The investigations were performed using optical and scanning electron microscopy with Field Emission Gun (FED) and X-ray Energy Dispersive Spectrometer (EDS). It is shown that the AlSi5Cu1Mg casting alloy, used for the fabrication of these couplings, presents a normal microstructure. Thus, the nucleation and growth of micro-cracks in the investigated couplings are not related to the alloy’s microstructural defects and must be generated by a different process.

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