Electrocatalytic Oxidation of Nitrite at Platinum Particles Modified Glassy Carbon Electrode

2012 ◽  
Vol 512-515 ◽  
pp. 2291-2294
Author(s):  
Yu Cui Hao ◽  
Li Shen ◽  
Zhi Ai

Platinum particles modified glassy carbon electrode(Pt/GCE)was prepared by electrochemically deposite. The electrochemica1 behaviors of nitrite on Pt/GCE were studied by cyclic voltammetry. The influence factors of electrocatalysis for nitrite oxidation on Pt/GCE were studied. The result showed that Pt/GCE has favorable electrocatalysis for nitrite. oxidation, which was effected by the amount of platinum particles and the pH of base solution

2012 ◽  
Vol 512-515 ◽  
pp. 2295-2299
Author(s):  
Xue Ping Liu ◽  
Hai Yan Kang ◽  
Wei Hua Chang ◽  
Min Ma

This paper describes the electrocatalytic oxidation of nitrite by poly-thionine /gold nanoparticle modified glassy carbon electrode. Due to the synergistic effect of poly-thionine and gold nanoparticle, the modied electrodes could oxide nitrite with enhanced oxidation current and a decrease in the required overpotential compared with bare electrode without poly-thionine and gold nanoparticles layer coated. The influence factors for nitrite assay such as polymer film thickness, adsorption time of gold nanoparticles onto the poly-thionine film, different buffers and pH,interferent ions were discussed elaborately. Under the optimal conditions, the oxidation current signal was proportional to the concentration of nitrite from 3.0×10-6 to 1.0×10-3 mol/L with a detection limit of 1.0×10-6 mol/L. The proposed method has been applied to determine nitrite concentration in real samples and the results were satisfactory. The poly-thionine/gold nanoparticles composites modied electrode has been proved to possess high sensitivity, good storage stability, reproducibility and anti-interference ability.


2020 ◽  
Vol 16 (4) ◽  
pp. 393-403 ◽  
Author(s):  
Renjini Sadhana ◽  
Pinky Abraham ◽  
Anithakumary Vidyadharan

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.


2011 ◽  
Vol 8 (2) ◽  
pp. 553-560 ◽  
Author(s):  
Mohammed Zidan ◽  
Tan Wee Tee ◽  
A. Halim Abdullah ◽  
Zulkarnain Zainal ◽  
Goh Joo Kheng

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.


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