scholarly journals Hemin-Modified SnO2/Metglas Electrodes for the Simultaneous Electrochemical and Magnetoelastic Sensing of H2O2

Coatings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 284 ◽  
Author(s):  
Georgios Samourgkanidis ◽  
Pavlos Nikolaou ◽  
Andreas Gkovosdis-Louvaris ◽  
Elias Sakellis ◽  
Ioanna Maria Blana ◽  
...  
Keyword(s):  
Electrochemical Sensor ◽  
Control Experiment ◽  
Direct Reduction ◽  
X Ray Diffraction ◽  
Film Layer ◽  
Ft Ir ◽  
Cv Measurements ◽  
Magnetoelastic Resonance ◽  
Mass Increase

In this work, we present a simple and efficient method for the preparation of hemin-modified SnO2 films on Metglas ribbon substrates for the development of a sensitive magneto-electrochemical sensor for the determination of H2O2. The SnO2 films were prepared at low temperatures, using a simple hydrothermal method, compatible with the Metglas surface. The SnO2 film layer was fully characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), photoluminescence (PL) and Fourier Transform-Infrared spectroscopy (FT-IR). The properties of the films enable a high hemin loading to be achieved in a stable and functional way. The Hemin/SnO2-Metglas system was simultaneously used as a working electrode (WE) for cyclic voltammetry (CV) measurements and as a magnetoelastic sensor excited by external coils, which drive it to resonance and interrogate it. The CV scans reveal direct reduction and oxidation of the immobilized hemin, as well as good electrocatalytic response for the reduction of H2O2. In addition, the magnetoelastic resonance (MR) technique allows the detection of any mass change during the electroreduction of H2O2 by the immobilized hemin on the Metglas surface. The experimental results revealed a mass increase on the sensor during the redox reaction, which was calculated to be 767 ng/μM. This behavior was not detected during the control experiment, where only the NaH2PO4 solution was present. The following results also showed a sensitive electrochemical sensor response linearly proportional to the concentration of H2O2 in the range 1 × 10−6–72 × 10−6 M, with a correlation coefficient of 0.987 and detection limit of 1.6 × 10−7 M. Moreover, the Hemin/SnO2-Metglas displayed a rapid response (30 s) to H2O2 and exhibits good stability, reproducibility and selectivity.

scholarly journals SOLID STATE CHARACTERIZATION OF A NOVEL PHYSICAL INTERACTION (PARACETAMOL-CHLORPHENIRAMINE MALEATE)

2018 ◽  
Vol 10 (1) ◽  
pp. 21
Author(s):  
Iyan Sopyan ◽  
Intan Mutiara Sari ◽  
Insan Sunan K.
Keyword(s):  
Solid State ◽  
Pure Substance ◽  
Physical Interaction ◽  
X Ray Diffraction ◽  
Chlorpheniramine Maleate ◽  
Pharmaceutical Dosage Form ◽  
Pharmaceutical Ingredients ◽  
Ft Ir

Objective: Interactions of active pharmaceutical ingredients (API) as well as pharmaceutical excipients don’t occur in a pharmaceutical dosage form. Base on structures of paracetamol (PCT) and chlorphenamine maleate (CTM), its combination is possible to give a physical interaction in the solid state. This study was conducted to investigate the physical interaction of PCT and CTM in the solid state.Methods: Characterization used the polarization microscope, solubility test, powder x-ray diffraction (PXRD) to observe peak shifting in 2Ɵ angle, and fourier transform infrared spectroscopy (FT-IR) to examine wavenumber shifting.Results: Results of solubility exhibited an increased solubility percentage with increasing concentration. Polarization microscope analysis presented a combination of crystal morphology after the two substances were mixed in an equimolar ratio. The result of melting point determination of each pure substance was 172 °C for PCT, 132 °C for CTM, and 170 °C for the mixture of the two substances in various ratios. Diffractogram showed the shifting at angle 2Ɵ: 20.715, 19.355-23.500 and 21.840, 26.455-20.330 for concentration ratio of PCT: CTM in (132:0.5) and (330:1) respectively and any change in the functional group was observed from infrared spectrum.Conclusion: All evaluation of PCT and CTM in the solid state has exhibited the interaction in solid condition.

Determination of Molecular Weight and Structure Characterization of Canna Amylose Purified Using the Method of n-Butanol Recrystallization

2012 ◽  
Vol 554-556 ◽  
pp. 1216-1222
Author(s):  
Hai Xin Shi ◽  
Yan Zhen Yin ◽  
Xiao Xi Hu ◽  
Shu Fei Jiao
Keyword(s):  
Molecular Weight ◽  
Average Molecular Weight ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Granule Surface ◽  
Chemical Groups ◽  
Ubbelohde Viscometer

The canna amylose (CAM) was separated from canna starch grown in China and purified both using the method of n-butanol recrystallization. The purity, morphology, spectral properties and molecular weight of CAM were characterized by ultraviolet and visible spectrophotometer (UV/Vis), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscope (FT-IR) and Ubbelohde viscometer. Maximum absorption wavelength of the purified CAM (635－638 nm) and it’s blue values (BV) (1.167 ± 0.209) prove that the purification of the CAM by n-butanol recrystallization was successfully carried out. The SEM results show that CAM granule surface become rougher and the CAM granule size become smaller than that of canna starch. The XRD results suggest that most of CAM granule is amorphous. And the FT-IR results show that the basic chemical groups of canna starch are also presented in CAM. However, the amorphous area of CAM is increased. The intrinsic viscosity and viscosity-average molecular weight of CAM is 78.5 mL/g and 1.65×105, respectively.

Colorimetric Detection of Hg(II) Sensor Based on Mos2 Nanosheets Acting as Peroxidase Mimics

2021 ◽  
Vol 37 (3) ◽  
pp. 679-682
Author(s):  
S. Kavitha ◽  
S. Mary Jelastin Kala ◽  
A. Anand Babu Christus
Keyword(s):  
Colorimetric Detection ◽  
High Sensitivity ◽  
Colorimetric Determination ◽  
X Ray Diffraction ◽  
Mos2 Nanosheets ◽  
Peroxidase Mimic ◽  
Sem Image ◽  
Peroxidase Mimics ◽  
Ft Ir

This paper presents colorimetric determination of Hg(II) based on MoS2 nanosheets with peroxidase mimics activity. The structure of the this sensor by the peroxidase mimic activity material of MoS2 nanosheets with TMB (Tetramethylbenzidine) solution, the colorimetric detection target of Hg(II) is determined by on-off mechanism using biomolecule of cysteine. The MoS2 nanosheets evaluated by X-ray diffraction, FT-IR and SEM image, confirms formation of a flower like structure. Our results shows that a simple colorimetric detection using peroxidase mimic mechanism can be used to MoS2 nanosheets and determine the Hg(II) in aqueous solution with high sensitivity (10 nM) comparable to those of other nanomaterials. The result suggests that MoS2 nanosheets is a promising new and simple colorimetric sensor for applications in environmental and biological applications.

Effect of Drinking Water on Formation of Renal Calculi

2009 ◽  
Vol 415 ◽  
pp. 37-40
Author(s):  
Ion Iosub ◽  
Viorel Malinovschi ◽  
Victor Grigorie ◽  
Alina Murariu ◽  
Aurelia Meghea
Keyword(s):  
Drinking Water ◽  
Renal Calculi ◽  
Quality Parameters ◽  
Point Of View ◽  
Human Organism ◽  
Kidney Calculi ◽  
X Ray Diffraction ◽  
Drinking Waters ◽  
Ft Ir

The environmental impact on human health is of increasing concern mainly due to the complex interaction between various hazardous factors both on environment and within human organism. The aim of this paper is to investigate possible correlations between the quality parameters of drinking water and the formation of uroliths. The constituents of some kidney calculi sampled after surgery from 90 patients coming from the Horezu – Valcea area have been analysed, this region being identified as having the most cases of kidney lithiasis and that might be related with hard drinking waters. The study has been made during the period of 2004 – 2008. Physical – chemical methods specific for characterization of the quality of drinking waters have been used in parallel with determination of composition and structural characterization by X-ray diffraction, thermal analysis TG, ATD, FT-IR spectroscopy, optical microscopy. Four groups of uroliths have been identified: multiphase oxalate and urate, phosphate (hydroxiapatite) and carbonate, monohydrated oxalate (whewellite), and urate stones. Such research might be useful, from both chemical and biochemical point of view, for identifying the conditions that cause the inhibition of the processes related to kidney calculi formation.

Comparison of FT-IR, Thermal Analysis and XRD for Determination of Products of Cement Hydration

2010 ◽  
Vol 168-170 ◽  
pp. 518-522 ◽  
Author(s):  
Zhi Hua Ou ◽  
Bao Guo Ma ◽  
Shou Wei Jian
Keyword(s):  
Thermal Analysis ◽  
Fourier Transform ◽  
Cement Hydration ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Cement Pastes ◽  
X Ray ◽  
Degree Of Hydration ◽  
Ft Ir

Fourier Transform Infrared Spectroscopy (FT-IR), thermal analysis and X-Ray Diffraction (XRD) are commonly performed to study the hydration products in cement pastes. The three methods were compared in this frame to detect products of cement hydration at different ages, especially at early ages (before 24h ages). The results indicate from the present experiment that CH (Calcium hydroxide) can be detected by three methods at all ages; C-S-H can be distinguished by FT-IR at all ages; ettringite may be detected by FT-IR before 24h ages and by XRD at all ages; and monosulphate can be detected by FT-IR before 24h ages. The process of cement hydration, characterized by formation and development of some hydration products, can be clearly observed by three methods. FT-IR is suggested for detecting the major hydration products before 24h ages, FT-IR and XRD are suggested for detecting the major hydration products after 24h ages, and thermal analysis is suggested for analyzing the degree of hydration quantitatively.

scholarly journals Preparation of Electrochemical Sensor Based on Zinc Oxide Nanoparticles for Simultaneous Determination of AA, DA, and UA

2020 ◽  
Vol 8 ◽  
Author(s):  
Yuanzhi Pan ◽  
Junli Zuo ◽  
Zhongyu Hou ◽  
Yizhong Huang ◽  
Cancan Huang
Keyword(s):  
Electrochemical Sensor ◽  
Simultaneous Determination ◽  
Modified Electrode ◽  
Zinc Oxide Nanoparticles ◽  
Clinical Applications ◽  
X Ray Diffraction ◽  
Modified Glassy Carbon Electrode ◽  
Zno Nps ◽  
X Ray

ZnO nanoparticles (NPs) were synthesized using a hydrothermal method. Scanning electron microscope (SEM) and X-ray diffraction have been used for characterizing the synthesized ZnO NPs. An electrochemical sensor was fabricated using ZnO NPs–modified glassy carbon electrode for simultaneous determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA). The proposed electrochemical sensor exhibited excellent detection performance toward three analytes, demonstrating that it can potentially be applied in clinical applications. The results indicated the ZnO NPs–modified electrode can detect AA in the concentrations range between 50 and 1,000 μM. The ZnO NPs–modified electrode can detect DA in the concentrations range between 2 and 150 μM. The ZnO NPs–modified electrode can detect UA in the concentrations range between 0.2 and 150 μM. The limits of detections of AA, DA, and UA using ZnO NPs–modified electrode were calculated to be 18.4, 0.75, and 0.11 μM, respectively.

scholarly journals Determination of Bisphenol A in Beverages by an Electrochemical Sensor Based on Rh2O3/Reduced Graphene Oxide Composites

2018 ◽  
Vol 8 (12) ◽  
pp. 2535 ◽  
Author(s):  
Rongguang Shi ◽  
Xiaoli Yuan ◽  
Aifeng Liu ◽  
Mengmeng Xu ◽  
Zongshan Zhao
Keyword(s):  
Graphene Oxide ◽  
Bisphenol A ◽  
Electrochemical Sensor ◽  
Reduced Graphene Oxide ◽  
X Ray Diffraction ◽  
Reduced Graphene ◽  
Simple Filtration ◽  
Oxide Composites ◽  
Excellent Stability

A novel electrochemical sensor, based on a Rh2O3–reduced graphene oxide (rGO) composite modified carbon electrode, has been developed for detecting bisphenol A (BPA) in beverages. The prepared Rh2O3/rGO and its precursor materials were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). Under optimum conditions, the sensor presented good electrochemical performance for analyzing BPA, with a linear range of 0.6–40 μM, detection limit of 0.12 μM, good reproducibility, and excellent stability. The good performance can be attributed to the combination of the good catalytic properties of Rh2O3 and good conductivity of rGO. The sensor is directly used for detecting BPA in the residual solutions of four beverages after simple filtration, with satisfactory recoveries of 93–99%.

Controllable Preparation of Multi-Morphology Nanosized Silica by Hydrolysis of Mixed Chlorosilanes in Mixed Solvent of Alcohol and Water

2010 ◽  
Vol 152-153 ◽  
pp. 1267-1271
Author(s):  
Jun Zhang ◽  
Bo Xu ◽  
Su Ping Hu ◽  
Yu Li Feng ◽  
Yan Hui Guo
Keyword(s):  
Aliphatic Alcohol ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Ft Ir ◽  
Formation Conditions ◽  
Hydrolysis Of ◽  
Controllable Preparation ◽  
Nanosized Silica

The nanosized silica with different morphologies such as sphere, granule, needle, short rod, hollow tubule, has been in turn synthesized by using cetyltrimethylammonium bromide (CTAB) as template and mixed chlorosilane (silicon tetrachloride and trichlorosilane) as silicon source in aliphatic alcohol aqueous solution. The as-prepared products were characterized by x-ray diffraction (XRD), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FT-IR), and BET nitrogen adsorption technique was employed for determination of specific surface area of the powdery silica. The formation conditions and mechanism of the nanosized silica with special and diverse shapes are preliminarily discussed.

scholarly journals Structural determination of new solid solutions [Y2-xMx][Sn2-xMx]o7-3x/2 (M = Mg or Zn) by Rietveld method

2010 ◽  
Vol 4 (4) ◽  
pp. 237-243 ◽  
Author(s):  
Mohamed Douma ◽  
Hossain El ◽  
Raquel Trujillano ◽  
Vicente Rives
Keyword(s):  
Solid Solutions ◽  
Rietveld Method ◽  
Structural Parameters ◽  
Pyrochlore Structure ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Pyrochlore Type ◽  
Ft Ir

New [Y2-xMx][Sn2-xMx]O7-3x/2 (0 ?x? 0.30 for M = Mg and 0 ?x? 0.36 for M = Zn) solid solutions with the pyrochlore structure were synthesized via high-temperature solid-state reaction method. Powder X-ray diffraction (PXRD) patterns and Fourier transform infrared (FT-IR) spectra showed that these materials are new non-stoichiometric solid solutions with the pyrochlore type structure. The structural parameters for the solids obtained were successfully determined by Rietveld refinement based on the analysis of the PXRD diagrams. Lattice parameter (a) of these solid solutions decreases when x increases in both series. All samples obtained have the pyrochlore structure Fd-3m, no. 227 (origin at center -3m) with M2+ (M = Mg2+ or Zn2+) cations in Y3+ and Sn4+ sites, thus creating vacancies in the anionic sublattice.

scholarly journals 3-Mercaptopropyltrimethoxysilane Modified Diatomite: Preparation and Application for Voltammetric Determination of Lead (II) and Cadmium (II)

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Dinh Quang Khieu ◽  
Bui Hai Dang Son ◽  
Vo Thi Thanh Chau ◽  
Pham Dinh Du ◽  
Nguyen Hai Phong ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Fourier Transformation ◽  
Treatment Temperature ◽  
Carbon Paste ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Paste Electrode ◽  
Modified Diatomite

In this study, functionalized diatomite was prepared by grafting of 3-mercaptopropyltrimethoxysilane (MPTMS) to diatomite (MPTMS-diatomite). The diatomite with thermal treatment from 100 to 700°C was functionalized by MPTMS under dry and humid conditions. The obtained MPTMS-diatomite was characterized by X-ray diffraction (XRD), thermal gravity-differential scanning calorimeter (TG-DSC), and Fourier transformation infrared (FT-IR). The results showed that an increase in treatment temperature seems to reduce the loading of MPTMS onto diatomite. The humidity of diatomite was favorable for the grafting of functional groups on the surface. The possible mechanisms of MPTMS loading to diatomite (MPTMS-diatomite) were also proposed. The performance of a carbon paste electrode (CPE) modified with MPTMS-diatomite in the simultaneous determination of Cd(II) and Pb(II) ions was addressed.

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