scholarly journals Cyclic voltammetry and electrochemical impedance spectroscopy analysis of Cr3+ doped Mg2SiO4 nanoparticles

2020 ◽  
Vol 17 (3) ◽  
pp. 207-213
Author(s):  
Ramachandra Naik ◽  
V. Revathi ◽  
H. Nagabhushana ◽  
K.M Girish ◽  
H.P Nagaswarupa
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Solution Combustion ◽  
Transfer Resistance ◽  
Oxidation Reduction ◽  
Temperature Solution

Low temperature solution combustion synthesized Cr3+(1- 4 mol%) doped Mg2SiO4 nanoparticles were analyzed by Powder X-ray Diffraction (PXRD), Fourier Transform Infra-Red (FTIR) spectroscopy, Cyclic voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) techniques. PXRD profile shows the samples are crystalline.FTIR spectra show MgO6 octahedral and Si-O bending and stretching modes.It was observed that, CV show excellent semi rectangular shaped voltammograms due to the oxidation reduction reactions and the reversibility of the reaction which suits for electric double layer capacitance.Charge transfer resistance (Rct) was found to be 10 Ωindicates the better electron transfer from one phase to another.

scholarly journals Performance Evaluation of Miniature Integrated Electrochemical Cells Fabricated Using LTCC Technology

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1314 ◽  
Author(s):  
Paulina Szymanowska ◽  
Damian Nowak ◽  
Tomasz Piasecki
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Protein Adsorption ◽  
Materials Science ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Electrochemical Cells ◽  
Transfer Resistance ◽  
Relative Change

Miniaturized and integrated analytical devices, including chemical sensors, are at the forefront of modern analytical chemistry. The construction of novel analytical tools takes advantage of contemporary micro- and nanotechnologies, as well as materials science and technology. Two electrochemical techniques were used in experiments: electrochemical impedance spectroscopy and cyclic voltammetry. The goal of this study was to investigate electron transfer resistance in a model solution containing Fe 2 + / 3 + ions and protein adsorption using integrated electrochemical cells with different geometry. Tests performed at various Fe 2 + / 3 + concentration allowed to verify that these cells work properly. The influence of bovine serum albumin adsorbing to the surface of the integrated electrochemical cells was investigated. In electrochemical impedance spectroscopy, the value of R c t increased with protein adsorption and the relative change of R c t was in range 21% to 55%. In cyclic voltammetry the decreasing amperometric response of the working electrode was used as evidence of protein adsorption on the electrode.

Supramolecular p-sulfonated calix[4,6,8]arene for tryptophan detection

2014 ◽  
Vol 92 (12) ◽  
pp. 1139-1144 ◽  
Author(s):  
Tao-Tao Pang ◽  
Li-Ming Du ◽  
Hai-Long Liu ◽  
Yun-Long Fu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Spectroscopy Analysis ◽  
Modeling Calculation ◽  
Potential Complex ◽  
Scanning Electron

Numerous techniques have focused on the ability of p-sulfonated calix[n]arene to form complexes with tryptophan. Scanning electron microscopy and Fourier transform infrared spectroscopy were utilized to study the organization and molecular structure of different layers of the electrode surface. Scanning electron microscopy results showed that SC4A displayed a cubic structure whereas SC6A and SC8A displayed dendrite structures. The electrochemical properties and potential complex formation between SCnA and tryptophan were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Cyclic voltammetry experiments showed that the gold electrode was successfully functionalized by self-assembled cysteamine and SC4A. Electrochemical impedance spectroscopy results showed the observation of the tryptophan–SCnA interaction and indicated that SC4A had the highest sensitivity to tryptophan and allowed 2.04 μg L−1 tryptophan to be detected. Electrochemical impedance spectroscopy analysis and molecular modeling calculation confirmed that SC4A has higher tryptophan sensitivity than SC6A and SC8A.

scholarly journals Characterization of Electrode Performance in Enzymatic Biofuel Cells Using Cyclic Voltammetry and Electrochemical Impedance Spectroscopy

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 782 ◽  
Author(s):  
Adama A. Bojang ◽  
Ho Shing Wu
Keyword(s):  
Mass Transfer ◽  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Electrochemical Analysis ◽  
Buffer Solution ◽  
Transfer Resistance ◽  
Electrode Performance

The main objective of this study was to examine the quantitative performance of the electrochemical redox reaction of glucose by glucosidase and oxygen with laccase in a phosphate buffer solution at pH 7.0. The characterization of electrode performance was performed by using electrochemical analysis such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The use of such electrochemical analysis (CV and EIS) enables a better understanding of the redox process, the charge transfer resistance, and, hence, the potential mass transfer among the electrode materials in phosphorus buffer solution. The experimental results show that the maximum power densities of the bioanode and the biocathode electrodes were 800 µA/cm2 and 600 µA/cm2, respectively. Both the bioanode and biocathode show high internal resistance. The occurrence of peak-separation shows an excellent mass-transfer mechanism and better chemical reactivity in the electrode.

scholarly journals Protection of Carbon Steel Rebars by Epoxy Coating with Smart Environmentally Friendly Microcapsules

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 113
Author(s):  
Jacob Ress ◽  
Ulises Martin ◽  
Juan Bosch ◽  
David M. Bastidas
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Protection ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Pore Solution ◽  
Control Sample ◽  
Chloride Ions ◽  
Epoxy Coating ◽  
Transfer Resistance

The protection of mild steel by modified epoxy coating containing colophony microencapsulated corrosion inhibitors was investigated in this study. The corrosion behavior of these epoxy coatings containing colophony microcapsules was studied by electrochemical analysis using cyclic potentiodynamic polarization and electrochemical impedance spectroscopy. The microcapsule coating showed decreased corrosion current densities of 2.75 × 10−8 and 3.21 × 10−8 A/cm2 along with corrosion potential values of 0.349 and 0.392 VSCE for simulated concrete pore solution and deionized water with 3.5 wt.% NaCl, respectively, indicating improved corrosion protection in both alkaline and neutral pH. Electrochemical impedance spectroscopy analysis also showed charge transfer resistance values over one order of magnitude higher than the control sample, corroborating the electrochemical corrosion potential and current density testing results. Overall, the use of colophony microcapsules showed improved corrosion protection in simulated concrete pore solution and DI water solutions containing chloride ions.

scholarly journals Deciphering the Disaggregation Mechanism of Amyloid Beta Aggregate by 4-(2-Hydroxyethyl)-1-Piperazinepropanesulfonic Acid Using Electrochemical Impedance Spectroscopy

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 788
Author(s):  
Hien T. Ngoc Le ◽  
Sungbo Cho
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Specific Binding ◽  
Amyloid Β ◽  
Electrochemical Measurement ◽  
Charge Transfer Resistance ◽  
Chemical Agent ◽  
Transfer Resistance ◽  
K Value

Aggregation of amyloid-β (aβ) peptides into toxic oligomers, fibrils, and plaques is central in the molecular pathogenesis of Alzheimer’s disease (AD) and is the primary focus of AD diagnostics. Disaggregation or elimination of toxic aβ aggregates in patients is important for delaying the progression of neurodegenerative disorders in AD. Recently, 4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid (EPPS) was introduced as a chemical agent that binds with toxic aβ aggregates and transforms them into monomers to reduce the negative effects of aβ aggregates in the brain. However, the mechanism of aβ disaggregation by EPPS has not yet been completely clarified. In this study, an electrochemical impedimetric immunosensor for aβ diagnostics was developed by immobilizing a specific anti-amyloid-β (aβ) antibody onto a self-assembled monolayer functionalized with a new interdigitated chain-shaped electrode (anti-aβ/SAM/ICE). To investigate the ability of EPPS in recognizing AD by extricating aβ aggregation, commercially available aβ aggregates (aβagg) were used. Electrochemical impedance spectroscopy was used to probe the changes in charge transfer resistance (Rct) of the immunosensor after the specific binding of biosensor with aβagg. The subsequent incubation of the aβagg complex with a specific concentration of EPPS at different time intervals divulged AD progression. The decline in the Rct of the immunosensor started at 10 min of EPPS incubation and continued to decrease gradually from 20 min, indicating that the accumulation of aβagg on the surface of the anti-aβ/SAM/ICE sensor has been extricated. Here, the kinetic disaggregation rate k value of aβagg was found to be 0.038. This innovative study using electrochemical measurement to investigate the mechanism of aβagg disaggregation by EPPS could provide a new perspective in monitoring the disaggregation periods of aβagg from oligomeric to monomeric form, and then support for the prediction and handling AD symptoms at different stages after treatment by a drug, EPPS.

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