Electrooxidation of DL-norvaline at Glassy Carbon Electrode: Approaching the Modified Electrode for Voltammetric Studies of Hydroquinone and Catechol

2014 ◽  
Vol 5 (1) ◽  
pp. 23-31
Author(s):  
Mahmoud M. Kamel
Keyword(s):  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Carbon Electrode ◽  
Voltammetric Studies

scholarly journals Electrochemical determination of ascorbic acid at p-phenylenediamine film-holes modified glassy carbon electrode

2015 ◽  
Vol 80 (9) ◽  
pp. 1161-1175 ◽  
Author(s):  
Bikila Olana ◽  
Shimeles Kitte ◽  
Tesfaye Soreta
Keyword(s):  
Ascorbic Acid ◽  
Detection Limit ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Linear Response ◽  
Modified Electrodes ◽  
Electrochemical Determination ◽  
Carbon Electrode

In this work the determination of ascorbic acid (AA) at glassy carbon electrode (GCE) modified with a perforated film produced by reduction of diazonium generated in situ from p-phenylenediamine (PD) is reported. Holes were intentionally created in the modifier film by stripping a pre-deposited gold nanoparticles. The modified electrodes were electrochemically characterized by common redox probes: hydroquinone, ferrocyanide and hexamineruthenium(III). The cyclic voltammetric and amperometric response of AA using the modified electrodes was compared with that of bare GCE. The bare GCE showed a linear response to AA in the concentration range of 5 mM to 45 mM with detection limit of 1.656 mM and the modified GCE showed a linear response to AA in the concentration range of 5 ?M to 45 ?M with detection limit of 0.123 ?M. The effect of potential intereferents on amperometric signal of AA at the modified GCE was examined and found to be minimal. The inter-electrode reproducibility, stability, and accuracy were determined. The modified electrode showed excellent inter-electrode reproducibility, accuracy and stability. The modified electrode reported is a promising candidate for use in electroanalysis of AA.

scholarly journals Electrochemical Determination of Trace Pb (II) by The Modified Glassy Carbon Electrode Compositing MultiWalled Carbon Nanotubes-Nafion-Bi Film

2020 ◽  
pp. 1-12
Keyword(s):  
Carbon Nanotubes ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Anodic Stripping Voltammetry ◽  
Electrochemical Sensing ◽  
Carbon Electrode ◽  
Bismuth Film ◽  
Modified Glassy Carbon Electrode

A modified glassy carbon electrode (GCE) compositing multi-walled carbon nanotubes (MWCNTs), Nafion and bismuth film was prepared and applied for the sensitive detection of trace Pb (II). MWCNTs were dispersed into ethanol by ultrasonication in the presence of Nafion and the nanotubes are coated onto the bare GCE. After that, an extra Nafion adhesion agent is added to the electrode. By the in situ plating, a bismuth film was fabricated on the MWCNTs-NA/GCE, making the desired electrode, MWCNTs-NA-Bi/GCE. The modified electrode was characterized by differential pulse anodic stripping voltammetry, scanning electron microscopy, and cyclic voltammetry. A deposition potential of –1.4 V (vs. Ag/AgCl) and a deposition time of 300 s were applied to the working electrode under stirred conditions after optimizing. Nanotubes and Nafion concentrations and pH were carefully optimized to determine trace lead ions by using the electrode as an electrochemical-sensing platform. Nafion effectively increased the stability and adhesivity of the composite film. The MWCNTs-NA-Bi film modified electrode can remarkably increase the anodic peak current of Pb2+. The sensitivity of MWCNTs-NA-Bi/GCE is 4.35 times higher than that of the bare GCE with bismuth film. The prepared electrode showed excellent stability and reproducibility and can be applied for determination of Pb2+ contained wastewater.

scholarly journals Electrocatalytic Study of Paracetamol at a Single-Walled Carbon Nanotube/Nickel Nanocomposite Modified Glassy Carbon Electrode

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Koh Sing Ngai ◽  
Wee Tee Tan ◽  
Zulkarnain Zainal ◽  
Ruzniza Mohd Zawawi ◽  
Joon Ching Juan
Keyword(s):  
Cyclic Voltammetry ◽  
Carbon Nanotube ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Carbon Electrode ◽  
Single Walled Carbon Nanotube ◽  
Paracetamol Concentration ◽  
Single Walled Carbon

A rapid, simple, and sensitive method for the electrochemical determination of paracetamol was developed. A single-walled carbon nanotube/nickel (SWCNT/Ni) nanocomposite was prepared and immobilized on a glassy carbon electrode (GCE) surface via mechanical attachment. This paper reports the voltammetry study on the effect of paracetamol concentration, scan rate, pH, and temperature at a SWCNT/Ni-modified electrode in the determination of paracetamol. The characterization of the SWCNT/Ni/GCE was performed by cyclic voltammetry. Variable pressure scanning electron microscopy (VPSEM) and energy dispersive X-ray (EDX) spectrometer were used to examine the surface morphology and elemental profile of the modified electrode, respectively. Cyclic voltammetry showed significant enhancement in peak current for the determination of paracetamol at the SWCNT/Ni-modified electrode. A linear calibration curve was obtained for the paracetamol concentration between 0.05 and 0.50 mM. The SWCNT/Ni/GCE displayed a sensitivity of 64 mA M−1and a detection limit of 1.17 × 10−7 M in paracetamol detection. The proposed electrode can be applied for the determination of paracetamol in real pharmaceutical samples with satisfactory performance. Results indicate that electrodes modified with SWCNT and nickel nanoparticles exhibit better electrocatalytic activity towards paracetamol.

Few-wall carbon nanotubes covalently functionalized by ferrocene groups for bioelectrochemical devices.

2012 ◽  
Vol 1451 ◽  
pp. 111-116
Author(s):  
Naoual Allali ◽  
Veronika Urbanova ◽  
Victor Mamane ◽  
Jeremy Waldbock ◽  
Mathieu Etienne ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electron Transfer ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Carbon Electrode ◽  
Ferrocene Derivatives ◽  
Covalent Functionalization ◽  
Side Walls ◽  
Chemical Groups

ABSTRACTThe present work reports the covalent functionalization of few-wall CNTs (FWCNTs) by ferrocene derivatives to i) improve their dispersion efficiency in water and ii) to graft electroactive chemical groups on their side-walls in order to promote electron transfer to biomolecules. The functionalized CNTs (f-CNTs) are used to modify a glassy carbon electrode and this modified electrode is used for oxidizing the cofactor NADH (dihydronicotinamide adenine dinucleotide).

Simultaneous determination of TBHQ and BHA on a MWNT-Brij® 35 modified electrode in micellar media

2015 ◽  
Vol 7 (19) ◽  
pp. 8344-8351 ◽  
Author(s):  
Guzel Ziyatdinova ◽  
Karina Os'kina ◽  
Endzhe Ziganshina ◽  
Herman Budnikov
Keyword(s):  
Simultaneous Determination ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Carbon Electrode ◽  
Micellar Medium ◽  
Micellar Media ◽  
Modified Glassy Carbon Electrode ◽  
Simultaneous Voltammetric Determination

Simultaneous voltammetric determination of TBHQ and BHA using a MWNT-Brij® 35 modified glassy carbon electrode in Brij® 35 micellar medium.

Electrocatalytic Response and Determination of Noradrenaline in the Presence of L-Ascorbic and Uric Acids with Poly(Eriochrome Black T)-Modified Electrode

2007 ◽  
Vol 72 (9) ◽  
pp. 1177-1188 ◽  
Author(s):  
Xinhua Lin ◽  
Wei Li ◽  
Hong Yao ◽  
Yuanyuan Sun ◽  
Liying Huang ◽  
...  
Keyword(s):  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Dynamic Range ◽  
Differential Pulse ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Eriochrome Black T ◽  
Wide Linear Dynamic Range

A poly(Eriochrome Black T) chemically modified glassy carbon electrode modified with Eriochrome Black T was prepared by cyclic voltammetry. The modified electrode showed an excellent electrocatalytic activity in oxidation of noradrenaline (NA) and could separate its electrochemical responses from those of L-ascorbic acid (AA) and uric acid (UA). Differences of the oxidation peak potentials for NA-AA and UA-NA were about 150 mV. The responses to NA, AA and UA of the modified electrode are relatively independent. Using differential pulse voltammetry, the peak currents of NA at modified glassy carbon electrode increased linearly with the concentration of NA from 0.5 to 100 μmol l-1. The detection limit was 0.2 μmol l-1. With the modified electrode, UA could be selectively determined in the presence of AA. The method showing a wide linear dynamic range and excellent sensitivity was successfully applied to the determination of NA in pharmaceutical injections and various samples.

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