Electrochemical Behavior and Determination of Rutin at Inlaid Multi-Wall Carbon Nanotubes Modified Graphite Electrode and Reline Ionic Liquids

2013 ◽  
Vol 785-786 ◽  
pp. 527-532 ◽  
Author(s):  
Li Qing Ye ◽  
Yan Zheng ◽  
Li Li Yan ◽  
Yun Tao Gao
Keyword(s):  
Carbon Nanotubes ◽  
Cyclic Voltammetry ◽  
Ionic Liquids ◽  
Electrochemical Behavior ◽  
Graphite Electrode ◽  
Oxidation Peak ◽  
Peak Current ◽  
Multi Wall Carbon Nanotubes ◽  
Oxidation Peak Current

Inlaid multi-wall carbon nanotubes modified graphite electrode (MWCNTs-GE) was fabricated, combined with Reline Ionic Liquids which possess high conductivity and wide electrochemical window, the electrochemical behavior and determination of Rutin was investigated by cyclic voltammetry and differential pulse stripping voltammetry. The result shows that the oxidation peak current of rutin increased obviously at the inlaid multi-wall carbon nanotubes modified graphite lectrode and in the Reline Ionic Liquids compared to that at the bare graphiteelectrode (GE). In phosphate buffer solution (pH=6.3), one pair of redox peak of rutin was obtained by cyclic voltammetry with 0.32 V of Epaand 0.24 V of Epc. The oxidation peak current value was linearly related to the concentration of rutin in the range of 2×10-6~3×10-5mol·L-1and the detection limit was 9.4×10-7mol·L-1. The average RSD of rutin was 4.0%. The average recovery was 100.2%. The inlaid multi-wall carbon nanotubes modified graphite electrode and the Reline Ionic Liquids had the function of electrocatalysis to oxidation of rutin obviously.This method is reliable, fast and convenient, sensitive and can be used for the determination of the content of rutin.

In situ detection of intermediates from the interaction of dissolved sulfide and manganese oxides with a platinum electrode in aqueous systems

2017 ◽  
Vol 14 (3) ◽  
pp. 178 ◽  
Author(s):  
Yao Luo ◽  
Yougang Shen ◽  
Lihu Liu ◽  
Jun Hong ◽  
Guohong Qiu ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Manganese Oxides ◽  
Platinum Electrode ◽  
Aqueous Systems ◽  
Oxidation Peak ◽  
Peak Current ◽  
Oxidation Peak Current ◽  
Dissolved Sulfide ◽  
In Situ Detection

Environmental contextDissolved sulfide results in soil acidification and subsequent contaminant leaching via oxidation processes, usually involving manganese oxides. In this work, redox processes were monitored in situ by cyclic voltammetry and HS– concentrations were semi-quantitatively determined. The method provides qualitative and semi-quantitative assessment for dissolved sulfide and its oxidation intermediates in aqueous systems. AbstractDissolved sulfide can be oxidised by manganese oxides in supergene environments, while the intermediates including S0, S2O32– and SO32– are easily oxidised by oxygen in air, resulting in some experimental errors in conventional analyses. In this work, the electrochemical behaviours of HS–, S2O32– and SO32– on a platinum electrode were studied by cyclic voltammetry and constant potential electrolysis, and in situ detection of the intermediates was conducted in aqueous systems of HS– and manganese oxides. The results showed that HS– was first oxidised to S0, and then transformed to SO42–. The peak current for the oxidation of HS– to S0 had a positive linear correlation with the used starting HS– concentration. S2O32– and SO32– were directly electrochemically oxidised to SO42–. The oxidation current peak potentials at 0, 0.45 and 0.7V were respectively observed for HS–, S2O32– and SO32– at pH 12.0. Cyclic voltammetry was conducted to monitor the redox processes of HS– and manganese oxides. The oxidation peak current of HS– to S0 decreased, and that of S2O32– to SO42– was observed to increase as the reaction proceeded. The rate of the decrease of the oxidation peak current of HS– indicated that the oxidation activity followed the order of birnessite>todorokite>manganite.

Differential Pulse Voltammetry Method for the Determination of Glucose on Multi-Nanostructured Active Electrode Modified by Platinum Nanoparticles

2012 ◽  
Vol 554-556 ◽  
pp. 440-444
Author(s):  
He Zhen Wu ◽  
Aie Cao ◽  
Di Lou Xu ◽  
Dao Bao Chu
Keyword(s):  
Differential Pulse Voltammetry ◽  
Platinum Nanoparticles ◽  
Glucose Concentration ◽  
Differential Pulse ◽  
Oxidation Peak ◽  
Active Electrode ◽  
Peak Current ◽  
Oxidation Peak Current ◽  
Pulse Voltammetry

Electrocatalytic oxidation of multi-nanostructured active electrode modified by platinum nanoparticles on glucose was examined. Based on 0.5mol/L KOH solution, we see a sensitive and good-shaped oxidation peak current near -0.77V (VS, SCE) by using differential pulse voltammetry method to scan in the range of -0.9~0.4V.The peak is regarded as the quantitative peak. There is a good linear relationship between glucose concentration and the peak current in the range of 1.0×10-2~1.0×10-5 mol/L. The linear correlation coefficient is 0.99864.The detection limit is 1.0×10-6mol/L. If added 0.06 m mol/L ascorbic acid or 0.3m mol/L uric acid (simulating human blood components), the determination of glucose is not interfered with. Results of the determination of glucose concentration in the blood are satisfactory.

Pd Doped Ag@C Core-Shell Nanocomposite for Electrochemical Sensitive Determination of Bisphenol A

2022 ◽  
Vol 905 ◽  
pp. 204-209
Author(s):  
Nan Dong ◽  
Ke Cao ◽  
Chen Xi Si ◽  
Dan Zheng
Keyword(s):  
Electron Microscopy ◽  
Bisphenol A ◽  
Differential Pulse ◽  
Core Shell ◽  
Oxidation Peak ◽  
Shell Nanoparticles ◽  
Peak Current ◽  
X Ray ◽  
Oxidation Peak Current

In this work, core–shell structured nanocomposites consisting of Pd doped Ag@C were synthesized by impregnation–reduction method. Then, sensing electrodes were fabricated by modifying Pd/Ag@C core-shell nanoparticles on screen-printed electrodes (SPE) for electrochemical determination of bisphenol A (BPA). The composition and morphology of nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, X ray diffraction and energy-dispersive X-ray spectroscopy. The electrochemical response characteristics of nanocomposites to BPA was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results indicated that, compared with Ag@C and Pd/C, Pd/Ag@C nanocomposite shows greater catalytic activity to the oxidation of BPA due to the synergistic effect of Pd and Ag. Among the four synthesized Pd/Ag@C-x (x=1-4) nanomaterials, the Pd/Ag@C-3 exhibits the best sensing performance toward the sensitive detection of BPA. The linear range for BPA determination was from 8.0×10-8 M to 1.5×10-5M with a detection limit of 1.0×10-8 M. A less than 9% oxidation peak current change was observed on the determination of BPA using Pd/Ag@C-3/SPE when added different interfering species into the BPA solution. The oxidation peak current attenuation of BPA on Pd/Ag@C-3/SPE within five weeks was found to be less than 3.6%.

scholarly journals A NEW ELECTROCHEMICAL SENSOR BASED ON MODIFIED CARBON NANOTUBE-GRAPHITE MIXTURE PASTE ELECTRODE FOR VOLTAMMETRIC DETERMINATION OF RESORCINOL

2017 ◽  
Vol 10 (12) ◽  
pp. 295 ◽  
Author(s):  
Manjunatha Jg
Keyword(s):  
Carbon Nanotube ◽  
Modified Electrode ◽  
Sodium Dodecyl ◽  
Variable Pressure ◽  
Oxidation Peak ◽  
Experimental Conditions ◽  
Peak Current ◽  
Oxidation Peak Current ◽  
Paste Electrode

Objective: A new carbon nanotube (CNT)-graphite mixture paste electrode modified by Sodium dodecyl sulfate (SDS) surfactant (SDSMCNTGMPE) was prepared and applied for sensitive electrochemical determination of resorcinol (RS).Method: Cyclic voltammetry, variable pressure scanning electron microscopy, and differential voltammetry were employed for the surface analysis of the bare CNT-graphite mixture paste electrode and SDSMCNTGMPE. Comparison between the unmodified electrode and modified electrode, the modified electrode oxidation peak current significantly improved. The effects of the pH, scan rate, and concentration of RS on the peak current were investigated.Results: Results indicated that the peak current of RS is highest in 0.2 M pH 7.0 phosphate buffer solutions and that the electrode reaction corresponds to a rate controlled process. Under optimized experimental conditions, the oxidation peak current of RS was linear over a concentration range of 2×10−6 to 1.0×10−3 M with a detection limit of 5.8×10−6 M and quantification limit of 19×10−6 M.Conclusion: The prepared sensor also shows other features such as good stability, reproducibility and repeatability. The proposed sensor exhibits good application toward the detection of RS in commercial RS lotion samples.

scholarly journals Electrochemical antioxidant screening and evaluation based on guanine and chitosan immobilized MoS2 nanosheet modified glassy carbon electrode (guanine/CS/MoS2/GCE)

2020 ◽  
Vol 18 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Ping Tang ◽  
Xiaosheng Tang ◽  
Shiyong Mei ◽  
Yixi Xie ◽  
Liangliang Liu ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Antioxidant Capacity ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Carbon Electrode ◽  
Oxidation Peak ◽  
Modified Glassy Carbon Electrode ◽  
Peak Current ◽  
Oxidation Peak Current ◽  
Antioxidant Capacities

AbstractIn this study, an electrochemical biosensor based on guanine and chitosan immobilized MoS2 nanosheet modified glassy carbon electrode (guanine/CS/MoS2/GCE) was developed and employed for antioxidant screening and antioxidant capacity evaluation. The oxidation peak current of guanine was improved and nearly tripled after modifications of chitosan and MoS2 nanosheet. The immobilized guanine could be damaged by hydroxyl radicals generated in Fenton solution. However, in the presence of antioxidants, the guanine was protected and the oxidation peak current of guanine increased. This process mimics the mechanism of antioxidant protection in human body. The factors affecting preparation of sensor and detection of antioxidant capacity were optimized. At the optimum conditions, the guanine/CS/MoS2/GCE showed wide linear range, low detection limit, satisfactory reproducibility and stability for detection. Ascorbic acid was used as a model antioxidant to evaluate the antioxidant capacity. A good linearity was observed with a correlation coefficient of 0.9959 in the concentrations between 0.5 and 4.0 mg L-1. The antioxidant capacities of three flavonoids were also tested and the rank of antioxidant capacities was ascorbic acid (51.84%), quercetin (45.82%), fisetin (34.39%) and catechin (16.99%). Due to the rapid measurement and low cost, this sensor could provide an available sensing platform for antioxidant screening and evaluation.

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