Determination of the Charge Transfer Parameters of 4,4'-(Ferrocene-1,1'-diyldivinylene)bis(benzo-15-crown-5) at Glassy Carbon Electrode

1997 ◽  
Vol 62 (11) ◽  
pp. 1690-1697
Author(s):  
Mohamed El-Metwally Ghoneim ◽  
Youssef Ibrahim Moharram ◽  
Norman Taylor
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Carbon Electrode ◽  
Peak Separation ◽  
Electrochemical Parameters ◽  
Oxidation Wave ◽  
Transfer Parameters ◽  
Digital Simulations ◽  
And Diffusion

Electrochemical parameters of 4,4'-(ferrocene-1,1'-diyldivinylene)bis(benzo-15-crown-5) were collected using cyclic voltammetry, chronoamperometry and chronopotentiometry at a glassy carbon electrode. One-electron quasi-reversible oxidation wave was obtained at Epa of 0.532 V and Epc of 0.387 V. The peak separation, ∆Ep, standard heterogeneous rate constant, k0, and diffusion coefficient, D, of the electrochemical species have been processed by convolution and deconvolution transformations. Digital simulations using the kinetic parameters were also performed.

scholarly journals Voltammetric determination of dopamine in the presence of uric acid using a 2-hydroxy-1-(1-hydroxynaphthyl-2-azo)- naphthalin-4-sulfonic acid modified glassy carbon electrode

2010 ◽  
Vol 75 (12) ◽  
pp. 1685-1699 ◽  
Author(s):  
Asghar Ensafi ◽  
Samira Dadkhah-Tehrani ◽  
B. Rezaei
Keyword(s):  
Uric Acid ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Sulfonic Acid ◽  
Reaction Rate Constant ◽  
Carbon Electrode ◽  
Electrochemical Behaviors ◽  
Peak Separation

A polymerized film of 2-hydroxy-1-(1-hydroxynaphthyl-2-azo)- naphthalin-4-sulfonic acid (HHNANSA) was prepared at the surface of a glassy carbon electrode by electropolymerization. The modified electrode was used for the simultaneous determination of dopamine (DA) and uric acid (UA). The electrochemical behaviors of the compounds at the surface of the modified electrode were studied using cyclic voltammetry, chronoamperometry, and square wave voltammetry (SWV). The experimental results indicated that the modified electrode exhibited an efficient electrocatalytic activity towards the oxidation of DA and UA, with a peak separation of about 140 mV at pH 5.0. Using chronoamperometry, the catalytic reaction rate constant was measured and found to equal to 1.23 ? 104 mol-1 L s-1. At pH 5.0, the catalytic peak currents linearly depended on the DA and/or UA concentrations in the range of 1.0 - 300 ?mol L-1 DA (two linear segments with different slopes) and 6.7 - 20 ?mol L-1 UA, using SWV. The detection limits for DA and UA were 0.25 ?mol L-1 and 1.17 ?mol L-1, respectively. The RSD % for 40.0 and 140.0 ?mol L-1 DA were 1.9 % and 2.2 %, respectively, whereas for 10.0 and 20.0 ?mol L-1 UA, they were 1.8 % and 1.2 %, respectively. The modified electrode showed good sensitivity, selectivity, and stability. It was successfully applied for the determination of DA and UA in real samples, such as drugs and urine.

Simultaneous Determination of Hydroquinone and Catechol at Poly-Histidine Film Modified Glassy Carbon Electrode

2013 ◽  
Vol 781-784 ◽  
pp. 89-92
Author(s):  
Qiu Xia Yang ◽  
Wei Ping Sui ◽  
Da Wei Fan ◽  
Guo Bao Li
Keyword(s):  
Simultaneous Determination ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Differential Pulse ◽  
Electrode Reaction ◽  
Carbon Electrode ◽  
Selective Determination ◽  
Peak Separation

The poly-histidine (poly-HTD) film was prepared at glassy carbon electrode by electropolymerization, and its electrochemical behavior was investigated by cyclic voltammetry. Results show that the behavior of this poly-HTD film is in good agreement with quasi-reversible process characteristic. At low scan rates, the electronic transfer process of electrode reaction is controlled by surface process. At this poly-HTD film modified electrode, an excellent electrocatalytic ability towards the redox of hydroquinone (HQ) and catechol (CC) with decrease of the overpotential and improvement of the redox peak currents was found. Differential pulse voltammetry was used for the simultaneous determination of HQ and CC in their mixture, and the peak-to-peak separation ΔEpfor HQ and CC was 110 mV. Therefore, this polymer modified electrode can be used for the simultaneously selective determination of HQ and CC without interference with each other.

Simultaneous Determination of Epinephrine and Tyrosine Using a Glassy Carbon Electrode Amplified with ZnO-Pt/CNTs Nanocomposite

2019 ◽  
Vol 15 (2) ◽  
pp. 166-171 ◽  
Author(s):  
Ali Samadzadeh ◽  
Iran Sheikhshoaie ◽  
Hassan Karimi-Maleh
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Simultaneous Analysis ◽  
Urine Samples ◽  
Carbon Electrode ◽  
Linear Dynamic ◽  
Biological Compounds ◽  
Blood And Urine Samples ◽  
Human Blood And Urine

Background: Simultaneous analysis of epinephrine and tyrosine as two effective and important biological compounds in human blood and urine samples are very important for the investigation of human health. Objective: In this research, a highly effective voltammetric sensor fabricated for simultaneous analysis of epinephrine and tyrosine. The sensor was fabricated by the modification of glassy carbon electrode with ZnO-Pt/CNTs nanocomposite (ZnO-Pt/CNTs/GCE). The synthesized nanocomposite was characterized by SEM method. The ZnO-Pt/CNTs/GCE showed two separated oxidation signals at potential ~220 mV and 700 mV for epinephrine and tyrosine, respectively. Also, we detected linear dynamic ranges 0.5-250.0 µM and 1.0-220 µM with a limit of detections 0.1 µM and 0.5 µM for the determination of epinephrine and tyrosine, respectively. The ZnO-Pt/CNTs/GCE was used for the determination of epinephrine and tyrosine in blood serum and human urine samples.

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