Pulse cyclic voltammetry. I. Static solutions

1987 ◽  
Vol 65 (5) ◽  
pp. 1051-1057 ◽  
Author(s):  
Gordon N. Eccles ◽  
William C. Purdy
Keyword(s):  
Cyclic Voltammetry ◽  
Detection Limit ◽  
Carbon Electrode ◽  
Peak Shape ◽  
Static Solutions ◽  
Scan Rate ◽  
Cyclic Voltammetry Test

By using pulse cyclic voltammetry rather than cyclic voltammetry at a relatively high scan rate, an increase in sensitivity and a lowering of the detection limit by more than a factor of two are demonstrated for the ferricyanide–ferrocyanide couple at a carbon electrode. The test for reversibility based on peak shape or symmetry comparison is enhanced significantly with pulse cyclic voltammetry. Another reversibility test, by observing peak variations as a function of scan rate, was applied to pulse cyclic voltammetry and was found to be as diagnostically informative as the cyclic voltammetry test. These tests are illustrated by a study of the hydroquinone–quinone couple.

scholarly journals Electrochemical Oxidation of Paracetamol Mediated byMgB2Microparticles Modified Glassy Carbon Electrode

2011 ◽  
Vol 8 (2) ◽  
pp. 553-560 ◽  
Author(s):  
Mohammed Zidan ◽  
Tan Wee Tee ◽  
A. Halim Abdullah ◽  
Zulkarnain Zainal ◽  
Goh Joo Kheng
Keyword(s):  
Cyclic Voltammetry ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Supporting Electrolyte ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Diffusion Controlled ◽  
Scan Rate ◽  
Degree Of Stability ◽  
A Current

A MgB2microparticles modified glassy carbon electrode (MgB2/GCE) was fabricated by adhering microparticles of MgB2onto the electrode surface of GCE. It was used as a working electrode for the detection of paracetamol in 0.1 M KH2PO4aqueous solution during cyclic voltammetry. Use of the MgB2/GCE the oxidation process of paracetamol with a current enhancement significantly by about 2.1 times. The detection limit of this modified electrode was found to be 30 μM. The sensitivity under conditions of cyclic voltammetry is significantly dependent on pH, supporting electrolyte, temperature and scan rate. The current enhancement observed in different electrolytic media varied in the following order: KH2PO4> KCl > K2SO4> KBr. Interestingly, the oxidation of paracetamol using modified GC electrode remain constant even after 15 cycling. It is therefore evident that the MgB2modifiedGCelectrode possesses some degree of stability. A slope of 0.52 dependent of scan rate on current indicates that the system undergoes diffusion-controlled process.

scholarly journals Methyldopa electrochemical sensor based on a glassy carbon electrode modified with Cu/TiO2 nanocomposite

2018 ◽  
Vol 83 (7-8) ◽  
pp. 863-874 ◽  
Author(s):  
Somayeh Tajik ◽  
Hadi Beitollahi ◽  
Pourya Biparva
Keyword(s):  
Cyclic Voltammetry ◽  
Detection Limit ◽  
Electrochemical Sensor ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Urine Samples ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Pulse Voltammetry ◽  
Practical Feasibility

A Cu/TiO2 nanocomposite modified glassy carbon electrode (Cu/ /TiO2/GCE) was fabricated to detect methyldopa by cyclic voltammetry (CV) and different pulse voltammetry (DPV) methods. Compared with bare GCE, the Cu/TiO2/GCE exhibited excellent electrochemical activity for the oxidation of methyldopa. Using DPV technique, the calibration curves for methyldopa were found linear in the concentration range of 0.5?800.0 ?M and the detection limit (S/N = 3) was calculated to be 0.23 ?M. Additionally, the prepared electrochemical sensor of Cu/TiO2/GCE demonstrated a practical feasibility in methyldopa tablets and in urine samples analysis.

scholarly journals Modification of Screen Printed Carbon Electrode (SPCE) with Fe3O4 for the Determination of Nitrite (NO2-) in Squarewave Voltammetry

Molekul ◽  
2017 ◽  
Vol 12 (2) ◽  
pp. 139 ◽  
Author(s):  
Erica Marista Rosida ◽  
Ani Mulyasuryani ◽  
Rachmat Triandi Tjahjanto
Keyword(s):  
Cyclic Voltammetry ◽  
Detection Limit ◽  
Carbon Electrode ◽  
Food Preservatives ◽  
Peak Current ◽  
Screen Printed Carbon Electrode ◽  
The Government ◽  
Selection Of ◽  
Screen Printed

Nitrite is one of the food preservatives that the government permits, but on the use of over limits can cause endanger health, so it is necessary to control the content of nitrite in the food. Modification of electrodes on a screen printed carbon electrode (SPCE) with Fe3O4 has been successfully done for determination of nitrite. Modification of the electrode has been done by electrodeposition with cyclic voltammetry. Electrodeposition successfully performed with an electrolyte solution of FeCl3 in ethanol. Selection of the optimum drying temperature modified electrode obtained based on the respond of the solution of nitrite in Britton Robinson buffer pH 8. The result of the modification electrode used for the determination of nitrite with squarewave voltammetry method. Reaction between Fe3+ with nitrite a basis for determining nitric indirectly measured so that the peak current is the peak current of Fe3+ of about 0,55 V vs Ag/AgCl. The results showed nitrite measurements with this method has a detection limit of 1.3 x 10-8 M.

Self-Assembled Graphene for Determination of Catechol in Wastewater at Modified Glassy Carbon Electrode

2012 ◽  
Vol 161 ◽  
pp. 255-259 ◽  
Author(s):  
Mei Feng Chen ◽  
Xin Ying Ma ◽  
Xia Li
Keyword(s):  
Cyclic Voltammetry ◽  
Detection Limit ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
High Sensitivity ◽  
Carbon Electrode ◽  
Oxidation Peak ◽  
Modified Glassy Carbon Electrode

Graphene-modified glassy carbon electrode was made by dropping. In phosphate-citric acid buffered saline, the modified electrode was shown to possess an excellent selective electrocatalytical effect on the redox of catechol, and further used to determine catechol in the presence of resorcin and hydroquinone by cyclic voltammetry. The oxidation peak currents Ipa showed a linear relationship with the concentrations (c) of catechol in the range of 2.97×10-7 mol•L-1~9.31×10-6 mol•L-1 and 9.31×10-6 mol•L-1~1.03×10-4 mol•L-1 with a correlation coefficient as follows: Ipa1(A)= -4.10×10-6-2.31c, R=0.Superscript text9971; Ipa2 (A) =-1.50×10-5-0.60c, R=0.9953, respectively, and the detection limit is 2.50×10-8 mol•L-1. The modified electrode is high sensitivity, selectivity, stability, and has been successfulSuperscript textly applied to analyzing catechol in wastewater.

scholarly journals Determinação de catequinas por eletrodo de carbono impresso modificado com nanotubo de carbono funcionalizado

2015 ◽  
Vol 40 (1) ◽  
pp. 52
Author(s):  
Ana Luísa Silva ◽  
Q. G. Da Silva ◽  
Lauro Tatsuo Kubota ◽  
A. T. Tanaka
Keyword(s):  
Blood Flow ◽  
Cyclic Voltammetry ◽  
Standard Deviation ◽  
Carbon Electrode ◽  
Cholesterol Levels ◽  
Linear Behavior ◽  
Analytical Curve ◽  
Scan Rate ◽  
Good Repeatability ◽  
Detection And Quantification

Catechin is a phenolic compound with high oxidizing potential, found in several types of foods, some of the benefits of catechins are capillary strengthening, improvement of blood flow and reduction of cholesterol levels. In this paper, it was used the cyclic voltammetry technique (CV) to optimize the printed carbon electrode modified with carbon nanotube, functionalized to detect and quantify catechin by means of the squarewave voltammetry technique (SWV). For this electrode, the best results were obtained at a catechin concentration of 1x10-3 mol L-1 in means of 0.1 mol L-1 phosphate buffer pH 7.0 at a potential scan rate of 0.05 V s-1. From these conditions, an analytical curve was obtained with a linear behavior in the catechin concentration range of 1,68x10-5 to 2,0x10-7 mol L-1, with limits of detection and quantification of 9,2x10-8 and 3,0x10-7 mol L-1, respectively, by SWV. This electrode showed good repeatability with a standard deviation of 4.05%. Oxidation of catechin showed a peak located around 0,15V vs Ag / AgCl, being close to the peak potentials shown in the literature.

Solar Exfoliated Graphene Oxide: A Platform for Electrochemical Sensing of Epinephrine

2020 ◽  
Vol 16 (4) ◽  
pp. 393-403 ◽  
Author(s):  
Renjini Sadhana ◽  
Pinky Abraham ◽  
Anithakumary Vidyadharan
Keyword(s):  
Cyclic Voltammetry ◽  
Graphene Oxide ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Simultaneous Detection ◽  
Differential Pulse ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Reduced Graphene ◽  
Pulse Voltammetry

Introduction: In this study, solar exfoliated graphite oxide modified glassy carbon electrode was used for the anodic oxidation of epinephrine in a phosphate buffer medium at pH7. The modified electrode showed fast response and sensitivity towards Epinephrine Molecule (EP). The electrode was characterized electrochemically through Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). Area of the electrode enhanced three times during modification and studies reveal that the oxidation process of EP occurs by an adsorption controlled process involving two electrons. The results showed a detection limit of 0.50 ± 0.01μM with a linear range up to 100 μM. The rate constant calculated for the electron transfer reaction is 1.35 s-1. The electrode was effective for simultaneous detection of EP in the presence of Ascorbic Acid (AA) and Uric Acid (UA) with well-resolved signals. The sensitivity, selectivity and stability of the sensor were also confirmed. Methods: Glassy carbon electrode modified by reduced graphene oxide was used for the detection and quantification of epinephrine using cyclic voltammetry and differential pulse voltammetry. Results: The results showed an enhancement in the electrocatalytic oxidation of epinephrine due to the increase in the effective surface area of the modified electrode. The anodic transfer coefficient, detection limit and electron transfer rate constant of the reaction were also calculated. Conclusion: The paper reports the determination of epinephrine using reduced graphene oxide modified glassy carbon electrode through CV and DPV. The sensor exhibited excellent reproducibility and repeatability for the detection of epinephrine and also its simultaneous detection of ascorbic acid and uric acid, which coexist in the biological system.

On the theory of cyclic voltammetry for multiple nucleation and growth: Scan rate influence

2021 ◽  
Vol 883 ◽  
pp. 115056
Author(s):  
Alexander V. Kosov ◽  
Olga V. Grishenkova ◽  
Olga L. Semerikova ◽  
Vladimir A. Isaev ◽  
Yurii P. Zaikov
Keyword(s):  
Cyclic Voltammetry ◽  
Nucleation And Growth ◽  
Scan Rate

scholarly journals Surfactant-free synthesis of carbon-supported silver (Ag/C) nanobars as an efficient electrocatalyst for alcohol tolerance and oxidation of sodium borohydride in alkaline medium

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Santanu Dey ◽  
Pradipta Chakraborty ◽  
Dhiraj Kumar Rana ◽  
Subhamay Pramanik ◽  
Soumen Basu
Keyword(s):  
Cyclic Voltammetry ◽  
Ethylene Glycol ◽  
Alkaline Medium ◽  
Sodium Borohydride ◽  
Metallic Silver ◽  
Alcohol Tolerance ◽  
Current Ratio ◽  
X Ray ◽  
Scan Rate ◽  
Borohydride Oxidation

AbstractWe have synthesized carbon-supported silver (Ag/C) nanobars by a simple surfactant-free hydrothermal method using glucose as the reducing reagent as well as the source of carbon in Ag/C nanobars. Physicochemical characterization of the materials was performed by X-ray Diffraction (XRD), field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The XRD pattern confirmed the presence of a pure metallic silver phase. No carbon phase was detected, which indicates that the carbon exists mainly in the amorphous form. The electrocatalytic activity of Ag/C in different electrolyte solutions such as 0.5 M NaOH, 0.5 M NaOH + 1 M ethanol (EtOH), 0.5 M NaOH + 1 M ethylene glycol (EG), and 0.5 M NaOH + 0.01 M NaBH4 (sodium borohydride) was studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA) study. Alcohol tolerance of the catalysts was also established in the presence of ethanol and ethylene glycol. The forward-to-backward current ratio from cyclic voltammetry (CV) study of Ag/C-20 (20 h) in 0.5 M NaOH + 1 M ethanol solution at 100 mV s−1 scan rate is 4.13 times higher compared to that of Ag/C-5 (5 h). Hence, Ag/C-20 is a better candidate for the tolerance of ethanol. In the presence of ethylene glycol (1 M) in 0.5 M NaOH solution, it is obtained that the forward-to-backward current ratio at the same scan rate for Ag/C-20 is lower than that in the presence of ethanol. The durability of the catalyst was studied by chronoamperometry measurement. We studied the electrochemical kinetics of Ag/C catalysts for borohydride oxidation in an alkaline medium. The basic electrochemical results for borohydride oxidation show that Ag/C has very well strength and activity for direct borohydride oxidation in an alkaline medium. The reaction of borohydride oxidation with the contemporaneous BH4−. hydrolysis was noticed at the oxidized silver surface. Among all the synthesized Ag/C catalysts, Ag/C-20 exhibited the best electrocatalytic performance for borohydride oxidation in an alkaline medium. The activation energy and the number of exchange electrons at Ag/C-20 electrode surface for borohydride electro-oxidation were estimated as 57.2 kJ mol−1 and 2.27, respectively.

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