scholarly journals A Water-Dispersible Carboxylated Carbon Nitride Nanoparticles-Based Electrochemical Platform for Direct Reporting of Hydroxyl Radical in Meat

Foods ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 40
Author(s):  
Tingting Han ◽  
Yang Huang ◽  
Chong Sun ◽  
Daoying Wang ◽  
Weimin Xu
Keyword(s):  
Hydroxyl Radical ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Great Promise ◽  
Signal Molecule ◽  
Water Dispersible ◽  
Transmission Electron ◽  
One Step ◽  
Meat Samples

In this paper, carboxylated carbon nitride nanoparticles (carboxylated-g-C3N4 NPs) were prepared through a one-step molten salts method. The synthesized material was characterized by transmission electron microscope (TEM), Fourier transform-infrared spectra (FTIR), and X-ray photoelectron spectroscopy (XPS), etc. An electrochemical sensor based on single-stranded oligonucleotide/carboxylated-g-C3N4/chitosan/glassy carbon electrode (ssDNA/carboxylated-g-C3N4/chitosan/GCE) was constructed for determination of the hydroxyl radical (•OH), and methylene blue (MB) was used as a signal molecule. The sensor showed a suitable electrochemical response toward •OH from 4.06 to 122.79 fM with a detection limit of 1.35 fM. The selectivity, reproducibility, and stability were also presented. Application of the sensor to real meat samples (i.e., pork, chicken, shrimp, and sausage) was performed, and the results indicated the proposed method could be used to detect •OH in practical samples. The proposed sensor holds a great promise to be applied in the fields of food safety.

scholarly journals Surface Study of CuO Nanopetals by Advanced Nanocharacterization Techniques with Enhanced Optical and Catalytic Properties

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1298 ◽  
Author(s):  
Muhammad Arif Khan ◽  
Nafarizal Nayan ◽  
Shadiullah Shadiullah ◽  
Mohd Khairul Ahmad ◽  
Chin Fhong Soon
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Properties ◽  
Average Length ◽  
Tem Analysis ◽  
X Ray ◽  
Surface Study ◽  
Transmission Electron ◽  
One Step ◽  
Controlled Morphology ◽  
Xrd Patterns

In the present work, a facile one-step hydrothermal synthesis of well-defined stabilized CuO nanopetals and its surface study by advanced nanocharacterization techniques for enhanced optical and catalytic properties has been investigated. Characterization by Transmission electron microscopy (TEM) analysis confirmed existence of high crystalline CuO nanopetals with average length and diameter of 1611.96 nm and 650.50 nm, respectively. The nanopetals are monodispersed with a large surface area, controlled morphology, and demonstrate the nanocrystalline nature with a monoclinic structure. The phase purity of the as-synthesized sample was confirmed by Raman spectroscopy and X-ray diffraction (XRD) patterns. A significantly wide absorption up to 800 nm and increased band gap were observed in CuO nanopetals. The valance band (VB) and conduction band (CB) positions at CuO surface are measured to be of +0.7 and −1.03 eV, respectively, using X-ray photoelectron spectroscopy (XPS), which would be very promising for efficient catalytic properties. Furthermore, the obtained CuO nanopetals in the presence of hydrogen peroxide ( H 2 O 2 ) achieved excellent catalytic activities for degradation of methylene blue (MB) under dark, with degradation rate > 99% after 90 min, which is significantly higher than reported in the literature. The enhanced catalytic activity was referred to the controlled morphology of monodispersed CuO nanopetals, co-operative role of H 2 O 2 and energy band structure. This work contributes to a new approach for extensive application opportunities in environmental improvement.

Effect of Gaseous Medium Pressure on Plasmadynamic Synthesis Product in the C-N System with Melamine

2014 ◽  
Vol 1040 ◽  
pp. 813-818 ◽  
Author(s):  
I.I. Shanenkov ◽  
Artur A. Sivkov ◽  
А.Ya. Pak ◽  
Yu.L. Kolganova
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Gaseous Medium ◽  
Morphological Changes ◽  
Nitrogen Pressure ◽  
Synthesis Product ◽  
X Ray Diffraction ◽  
Capacitive Energy Storage ◽  
X Ray ◽  
Transmission Electron

The possibility of plasmodynamic synthesis in the carbon-nitrogen system when using melamine as a precursor is described in the paper. The system based on the capacitive energy storage, which allows simultaneously powering the two opposite-directed coaxial magnetoplasma accelerators, is developed. The effect of gaseous medium in the processing chamber of the system on the synthesis product is investigated by applying such techniques as X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It is demonstrated that an increase in nitrogen pressure results in the structural and morphological changes in the synthesized sample, which might be caused by the increased carbon nitride yield and a great number of the appearing C-N bonds.

Activation of persulfate by heterogeneous catalyst ZnCo2O4–RGO for efficient degradation of bisphenol A

2020 ◽  
Vol 98 (12) ◽  
pp. 771-778
Author(s):  
Xin Chang ◽  
Xiangyang Xu ◽  
Zhifeng Gao ◽  
Yingrui Tao ◽  
Yixuan Yin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bisphenol A ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
One Step ◽  
Application Potential

A nanocomposite, reduced graphene oxide (RGO) modified ZnCo2O4 (ZnCo2O4–RGO) was synthesized via one-step solvothermal method for activating persulfate (PS) to degrade bisphenol A (BPA). The morphology and structure of the nanocomposite were identified by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. RGO provides nucleation sites for ZnCo2O4 to grow and inhibits the agglomeration of the nanoparticles. The influence of different reaction conditions on the oxidation of BPA catalyzed by ZnCo2O4–RGO was investigated, including the content of RGO, the dosage of catalyst, the concentration of humic acid (HA), anions in the environment, the reaction temperature, and pH. BPA can be totally degraded within 20 min under optimized reaction conditions. The presence of HA, Cl−, and NO3− only has a slight effect on the oxidation of BPA, whereas the presence of either H2PO4− or HCO3− can greatly inhibit the reaction. ZnCo2O4–RGO shows good cycling stability and practical application potential. A reaction mechanism of the degradation of BPA was also explored.

scholarly journals Efficient Method for the Concentration Determination of Fmoc Groups Incorporated in the Core-Shell Materials by Fmoc–Glycine

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3983
Author(s):  
Elżbieta Szczepańska ◽  
Beata Grobelna ◽  
Jacek Ryl ◽  
Amanda Kulpa ◽  
Tadeusz Ossowski ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Core Shell ◽  
Amino Groups ◽  
The Core ◽  
Transmission Electron ◽  
Model Sample ◽  
Vis Spectroscopy ◽  
Fmoc Group ◽  
Synthesis Procedure

In this paper, we described the synthesis procedure of TiO2@SiO2 core-shell modified with 3-(aminopropyl)trimethoxysilane (APTMS). The chemical attachment of Fmoc–glycine (Fmoc–Gly–OH) at the surface of the core-shell structure was performed to determine the amount of active amino groups on the basis of the amount of Fmoc group calculation. We characterized nanostructures using various methods: transmission electron microscope (TEM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) to confirm the modification effectiveness. The ultraviolet-visible spectroscopy (UV-vis) measurement was adopted for the quantitative determination of amino groups present on the TiO2@SiO2 core-shell surface by determination of Fmoc substitution. The nanomaterials were functionalized by Fmoc–Gly–OH and then the fluorenylmethyloxycarbonyl (Fmoc) group was cleaved using 20% (v/v) solution of piperidine in DMF. This reaction led to the formation of a dibenzofulvene–piperidine adduct enabling the estimation of free Fmoc groups by measurement the maximum absorption at 289 and 301 nm using UV-vis spectroscopy. The calculations of Fmoc loading on core-shell materials was performed using different molar absorption coefficient: 5800 and 6089 dm3 × mol−1 × cm−1 for λ = 289 nm and both 7800 and 8021 dm3 × mol−1 × cm−1 for λ = 301 nm. The obtained results indicate that amount of Fmoc groups present on TiO2@SiO2–(CH2)3–NH2 was calculated at 6 to 9 µmol/g. Furthermore, all measurements were compared with Fmoc–Gly–OH used as the model sample.

A Facile, “Green” One – Step, Room Temperature Synthesis of a Series of monodispersed MSe(M = Cd or Zn) Water Dispersible Nanoparticles

2008 ◽  
Vol 1138 ◽  
Author(s):  
Oluwatobi S. Oluwafemi ◽  
Neerish Revaprasadu
Keyword(s):  
Room Temperature ◽  
Metal Salt ◽  
Water Soluble ◽  
Synthetic Approach ◽  
Temperature Synthesis ◽  
Water Dispersible ◽  
Aspect Ratios ◽  
Transmission Electron ◽  
One Step ◽  
Capping Ligands

AbstractWe herein report a facile, ‘green’ one- step synthesis of a series of monodispersed water-soluble selenide nanoparticles at room temperature. The capping ligands used include, cysteine, methionine, ascorbic acid and starch which function as agents of solubilisation, stabilization and conjugation sites for biomolecules. The synthetic approach involves the addition of an appropriate volume of selenide ion produced via the reduction of selenium powder in water to an aqueous solution containing the ligand- metal salt (MCl2 M = Zn or Cd). Optical spectroscopy shows that the particles are of high quality while the transmission electron microscopy (TEM) of the samples shows variation in shapes ranging from dots to rods of high and low aspect ratios.

One-step synthesis of Sb2O3 broom-like belts with controllable morphology

2005 ◽  
Vol 83 (8) ◽  
pp. 1093-1097 ◽  
Author(s):  
Qingrui Zhao ◽  
Xuanjun Zhang ◽  
Qing Yang ◽  
Yi Xie
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Solvothermal Reaction ◽  
Antimony Trioxide ◽  
Reactant Ratio ◽  
Reaction Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
One Step ◽  
Template Free

A direct and simple surfactant- and template-free route has been developed for the controlled synthesis of Sb2O3 belt-like microstructures. By adjusting the reactant ratio between SbCl3 and urea under solvothermal reaction conditions, broom-like belts and rods of Sb2O3 have been successfully prepared. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS) has been used to characterize the phases and morphologies of the as-prepared products. A possible formation mechanism is also discussed.Key words: antimony trioxide, solvothermal synthesis, broom-like belts.

scholarly journals Facile Synthesis and Characterization of Au Nanoclusters-Silica Fluorescent Composite Nanospheres

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Huiping Wang ◽  
Chaoyong Xu ◽  
Chengzhi Zheng ◽  
Wei Xu ◽  
Tianjiao Dong ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Acetate Buffer Solution ◽  
Fluorescent Properties ◽  
Buffer Solution ◽  
Au Nanoclusters ◽  
Water Dispersible ◽  
Transmission Electron ◽  
Microscope Imaging ◽  
Novel Method

We developed a novel method for the synthesis of Au nanoclusters (NCs) silica fluorescent composite nanospheres by mixing the as-prepared bovine serum albumin (BSA) protected Au NCs with amino-modified silica spheres in acetate buffer solution. The products were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), fluorescent microscope imaging (FLMI), and dynamic light scattering (DLS) measurements. The proposed method was simple, efficient, and inexpensive. In addition, the composite nanospheres exhibited favorable water-dispersible, stable, and fluorescent properties, potentially leading to further applications in chemical and biological sensors. A reasonable mechanism was also proposed for the formation of composite nanospheres.

scholarly journals One-Step Hydrothermal Synthesis of N, Fe-Codoped Carbon Dots as Mimic Peroxidase and Application on Hydrogen Peroxide and Glucose Detection

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yan Li ◽  
Yuhui Weng ◽  
Shikong Lu ◽  
Meihua Xue ◽  
Bixia Yao ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Photoelectron Spectroscopy ◽  
Carbon Dots ◽  
Color Change ◽  
Limit Of Detection ◽  
Colorimetric Detection ◽  
Catalytic Efficiency ◽  
Transmission Electron ◽  
One Step ◽  
First Time

In this paper, N, Fe-codoped carbon dots (N, Fe-CDs) were synthesized from β-cyclodextrin, ethylenediamine, and ferric chloride for the first time using a convenient one-step hydrothermal method. The obtained N, Fe-CDs were characterized by various methods including transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The N, Fe-CDs exhibited better catalytic activity than horseradish peroxidase (HRP) and caused an evident color change for 3,3′,5,5′-tetramethylbenzidine in the presence of H2O2. Kinetic experiments show that the apparent Km value for the N, Fe-CDs with TMB (0.40 mM) or H2O2 (0.35 mM) as the substrate was lower than that of HRP (0.43 and 3.70 mM), suggesting that the N, Fe-CDs have a much higher affinity for TMB and H2O2 than HRP. The Km/Vmax value for the N, Fe-CDs (21.74×103·s for H2O2) is significantly lower than that for HRP (42.53×103·s), suggesting that the N, Fe-CDs have a stronger catalytic efficiency for H2O2 than HRP. Furthermore, a highly efficient and sensitive colorimetric detection method for glucose was developed using the N, Fe-CDs as mimic peroxidase to detect the hydrogen peroxide generated by the oxidation of glucose by glucose oxidase. The limit of detection for H2O2 and glucose was found to be 0.52 and 3.0 μM, respectively. The obtained N, Fe-codoped carbon dots, which possess simulated peroxidase activity, can potentially be used in the field of biotechnology.

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