Application of a Novel Modified Electrode Based on NaY-Encapsulated Co(PAN) Complex

2008 ◽  
Vol 587-588 ◽  
pp. 109-113
Author(s):  
C. Teixeira ◽  
P. Parpot ◽  
Isabel Neves ◽  
António Maurício C. Fonseca
Keyword(s):  
Cyclic Voltammetry ◽  
Chemical Analysis ◽  
Aqueous Medium ◽  
Surface Analysis ◽  
Modified Electrode ◽  
Modified Electrodes ◽  
Redox Properties ◽  
New Method ◽  
Y Zeolite

CoPAN complex has been entrapped in the supercages of Y zeolite and the redox properties of this zeolite-encapsulated complex were investigated by cyclic voltammetry with a new method for the preparation of carbon toray-zeolite-modified electrode. Formation of the CoPAN complex was ascertained by surface analysis (SEM, XRD), chemical analysis (CA), spectroscopy methods (FTIR and UV/vis) and cyclic voltammetry in aqueous medium with zeolite-modified electrodes. The cyclic voltammetry studies obtained with a zeolite-modified electrode shows evidence for electroactivity restricted to boundary associated CoPAN complex.

Electrooxidation for Methanol on Pd Nanoparticles Modified Electrodes in Alkaline Medium

2012 ◽  
Vol 535-537 ◽  
pp. 431-435
Author(s):  
Ming Li Xu ◽  
Guo Tao Yang
Keyword(s):  
Cyclic Voltammetry ◽  
Catalytic Oxidation ◽  
Modified Electrode ◽  
Palladium Nanoparticles ◽  
Modified Electrodes ◽  
Pd Nanoparticles ◽  
Catalytic Performance ◽  
Electrochemical Process ◽  
Glassy Carbon Electrodes ◽  
Cyclic Voltammetry Method

In this paper, Palladium nanoparticles were electrodeposited on the surface of glassy carbon electrodes by more circles cyclic voltammetry method and Palladium nanoparticles modified electrode (Pd/GCE) was obtained. Morphology and crystal structure of nanoparticles were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The performance and electrochemical process of catalytic oxidation methanol were measured and analyzed by cyclic voltammetry (CV), chronoamperometric curves (i-t) and alternating current impedance spectra (AC impedance) in KOH solution. The results showed that catalytic activity of Pd nanoparticles modified electrode for methanol was over 30 times higher than that of the plate Pd electrode, and catalytic performance was good. In addition, the catalytic oxidation was mainly diffusion-controlled process.

The Preparation, Characterization and Application of the CNTs Modified Electrode

2011 ◽  
Vol 694 ◽  
pp. 838-841
Author(s):  
Xue Mei Cui ◽  
Gui Fu Ding ◽  
Yan Wang ◽  
Wen Jing Lu ◽  
Hui Shen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cyclic Voltammetry ◽  
Composite Film ◽  
Field Emission ◽  
Modified Electrode ◽  
Modified Electrodes ◽  
Preparation Technology ◽  
Chemical Etch ◽  
Scanning Electron

We propose a novel preparation technology of CNTs modified electrode. CNTs are mixed with polymer into homogenate by mechanical ball grinder; spin homogenate into composite film; solidify and polish composite film; chemical etch polymer partly from the surface of the composite film, in order to keep part of the CNTs be inserted in polyimide and the remainder outside of film, then CNTs modified electrode can be got. The morphologies of CNTs modified electrode are observed by field emission scanning electron microscopy (FESEM). The application of CNTs modified electrode in alum solution battery is demonstrated. Cyclic voltammetry of CNTs modified electrodes in V4+ solution is discussed.

Preparation of Copper Doped L-Threonine Modified Electrode and its Application in Determination of Hydroquinone

2013 ◽  
Vol 813 ◽  
pp. 413-418
Author(s):  
Yue Hua ◽  
Zong Rong Song ◽  
Jia Hong He ◽  
Ying Zhang ◽  
Cheng Bo Hu
Keyword(s):  
Cyclic Voltammetry ◽  
Modified Electrode ◽  
Supporting Electrolyte ◽  
Modified Electrodes ◽  
Differential Pulse ◽  
Determination Method ◽  
Scan Rate ◽  
Anodic Peak Current ◽  
Pulse Voltammetry

A copper doped L-threonine modified electrode was prepared by cyclic voltammetry (CV), and the electrochemical behavior of hydroquinone at the modified electrode had been studied. A novel determination method of hydroquinone using CV, chronoamperometry and differential pulse voltammetry (DPV) was established, and the scan rate and supporting electrolyte factors on catalytic oxidation of hydroquinone in modified electrodes were discussed. The results revealed that the modified electrode had showed obvious electrocatalytic activity for hydroquinone, and anodic peak current increased linearly with the concentration of hydroquinone in the range of 0.8-150 μmol/L with the detection limit of 0.4 μmol/L (S/N=3). The method has been applied to the determination of hydroquinone in water sample with satisfactory results.the recovery ranged from 95.9 % to 105.2 %.

scholarly journals Ruthenium Oxide Hexacyanoferrate as an Effective Electrode Modifier for Amperometric Detection of Iodate and Hydrogen Peroxide

2020 ◽  
Vol 67 (4) ◽  
pp. 1216-1226
Author(s):  
Totka Dodevska ◽  
Ivan Shterev ◽  
Yanna Lazarova ◽  
Dobrin Hadzhiev
Keyword(s):  
Hydrogen Peroxide ◽  
Cyclic Voltammetry ◽  
Modified Electrode ◽  
Electrochemical Behaviour ◽  
Electrochemical Techniques ◽  
Ruthenium Oxide ◽  
Amperometric Detection ◽  
Modified Electrodes ◽  
Fast Response ◽  
High Catalytic Activity

Ruthenium oxide hexacyanoferrate (RuOHCF) film was electrochemically deposited onto a glassy carbon (GC) surface using consecutive cyclic voltammetry as a facile and green synthetic strategy. The electrochemical behaviour and electrocatalytic properties of the modified electrode RuОHCF/GC were evaluated with regards to electroreduction of hydrogen peroxide and iodate in a strong acidic medium (pHs 1.0–2.0) by using different electrochemical techniques, including cyclic voltammetry and amperometry at a constant potential. Electrochemical studies indicated that RuОHCF/GC possess a high catalytic activity in both studied reactions, fast response and good reproducibility of the current signal. The RuОHCF/GC exhibits enhanced electrocatalytic behaviour compared with other modified electrodes reported before. The simple and reproducible procedure for electrode fabrication, the wide linear range, anti-interference performance and long-time stability of the RuОHCF/GC make it a promising sensing material for practical quantitative determination of hydrogen peroxide and iodate. Remarkably, the reported modified electrode provided superior sensitive (1050 μA mM–1 cm–2) and highly selective amperometric detection of iodate.

Integrity and redox properties of homogeneous and heterogeneous DNA films on gold surface probed by cyclic voltammetry

2002 ◽  
Vol 413 (1-2) ◽  
pp. 218-223 ◽  
Author(s):  
Hellas C.M Yau ◽  
Hing Leung Chan ◽  
Sen-fang Sui ◽  
Mengsu Yang
Keyword(s):  
Cyclic Voltammetry ◽  
Gold Surface ◽  
Redox Properties ◽  
Dna Films

The Electrochemical Biosensor Based on the Immobilization of Horseradish Peroxidase on TiO2 Nanoneedles Modified Electrodes

2011 ◽  
Vol 239-242 ◽  
pp. 2499-2502
Author(s):  
Nan Nan Wei ◽  
Jiang Yan Du
Keyword(s):  
Horseradish Peroxidase ◽  
Modified Electrode ◽  
Electrochemical Biosensor ◽  
Signal To Noise Ratio ◽  
Direct Electron Transfer ◽  
Modified Electrodes ◽  
Signal To Noise ◽  
Formal Potential ◽  
Amperometric Response ◽  
Transfer Study

A new electrochemical biosensor based on the immobilization of horseradish peroxidase(HRP) on TiO2 nanoneedles modified electrodes has been fabricated. The direct electrochemical response of HRP immobilized on the modified electrode was dramatically enhanced. The immobilized HRP displayed a couple of stable and well-defined redox peaks with a formal potential of -0.379 V (vs. SCE). The HRP/TiO2 nanoneedles modified electrode exhibited a remarkable electrocatalytic activity toward the oxidation of H2O2. The amperometric response to H2O2 showed a linear range of 4–700μmol/L, with the calculated detection limit of 0.78 μmol/L at a signal-to-noise ratio of three. The modified electrode displayed an acceptable reproducibility and good stability. The new HRP/TiO2 nanoneedles matrix is expected to have wide applications for enzymes and proteins immobilization and direct electron transfer study and opened a way for low conductivity electrode biosensors.

Nickel(II) and Iron(II) Complexes with Tetradentate NHC/Amide Hybrid Ligands

2013 ◽  
Vol 68 (5-6) ◽  
pp. 458-466 ◽  
Author(s):  
Iris Klawitter ◽  
Steffen Meyer ◽  
Serhiy Demeshko ◽  
Franc Meyer
Keyword(s):  
Cyclic Voltammetry ◽  
Redox Properties ◽  
Spin States ◽  
Imidazolium Salts ◽  
Tetradentate Ligands ◽  
Square Planar ◽  
Hybrid Ligands

Two methylene-bridged bis(imidazolium) salts [H4L1](PF6)2 and [H4L2](PF6)2 with appended amide groups have been synthesized which, after deprotonation, may serve as potentially tetradentate ligands providing two bis(imidazole-2-ylidene) and two amide donors. Using [H4L1](PF6)2, a square-planar nickel(II) complex [NiL1] and a six-coordinate bis(ligand) iron(II) complex [Fe(HL1)2] have been isolated and structurally characterized. Their low-spin states have been confirmed spectroscopically, and their redox properties have been studied by cyclic voltammetry. Oxidations are metal-centered to give NiIII and FeIII species, respectively

scholarly journals An Electrochemical Cholesterol Biosensor Based on A CdTe/CdSe/ZnSe Quantum Dots—Poly (Propylene Imine) Dendrimer Nanocomposite Immobilisation Layer

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3368 ◽  
Author(s):  
Kefilwe Mokwebo ◽  
Oluwatobi Oluwafemi ◽  
Omotayo Arotiba
Keyword(s):  
Quantum Dots ◽  
Modified Electrode ◽  
Cholesterol Oxidase ◽  
Shell Growth ◽  
Modified Electrodes ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Poly Propylene ◽  
Cholesterol Biosensor

We report the preparation of poly (propylene imine) dendrimer (PPI) and CdTe/CdSe/ZnSe quantum dots (QDs) as a suitable platform for the development of an enzyme-based electrochemical cholesterol biosensor with enhanced analytical performance. The mercaptopropionic acid (MPA)-capped CdTe/CdSe/ZnSe QDs was synthesized in an aqueous phase and characterized using photoluminescence (PL) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), X-ray power diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy. The absorption and emission maxima of the QDs red shifted as the reaction time and shell growth increased, indicating the formation of CdTe/CdSe/ZnSe QDs. PPI was electrodeposited on a glassy carbon electrode followed by the deposition (by deep coating) attachment of the QDs onto the PPI dendrimer modified electrode using 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS) as a coupling agent. The biosensor was prepared by incubating the PPI/QDs modified electrode into a solution of cholesterol oxidase (ChOx) for 6 h. The modified electrodes were characterized by voltammetry and impedance spectroscopy. Since efficient electron transfer process between the enzyme cholesterol oxidase (ChOx) and the PPI/QDs-modified electrode was achieved, the cholesterol biosensor (GCE/PPI/QDs/ChOx) was able to detect cholesterol in the range 0.1–10 mM with a detection limit (LOD) of 0.075 mM and sensitivity of 111.16 μA mM−1 cm−2. The biosensor was stable for over a month and had greater selectivity towards the cholesterol molecule.

scholarly journals Cyclic Voltammetric Investigations of Thiazine Dyes on Modified Electrodes

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Amitabha Chakraborty ◽  
Shamsuzzaman Ahamed ◽  
Subrata Pal ◽  
Swapan K. Saha
Keyword(s):  
Diffusion Coefficient ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Electrochemical Behavior ◽  
Modified Electrodes ◽  
Electron Hopping ◽  
Cyclic Voltammetric ◽  
Peak Current ◽  
Quantitative Characteristics ◽  
Thiazine Dyes

Electrochemical behavior of five progressively alkylated thiazine dyes has been investigated at glassy carbon/montmorillonite and glassy carbon/zeolite electrodes. Quantitative characteristics, associated with the positions of peak potentials (Ea and Ec) and current ratios (ia/ic), are measured with scan rates. The peak current observed in the modified electrodes is dependent on both the porosity and nature and number of sites involved in partitioning the complex into film. The values of diffusion coefficient for different dyes have been calculated from electrochemical data. It is suggested that in clay-modified electrode along with physical diffusion the process of electron hopping seems to be most likely.

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