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 behaviors and electrochemical determination of carbamazepine at ionic liquid modified carbon paste electrode in the presence of sodium dodecyl sulfate

2012 ◽  
Vol 77 (4) ◽  
pp. 483-496 ◽  
Author(s):  
Li-Hong Liu ◽  
Cheng-Qian Duan ◽  
Zuo-Ning Gao
Keyword(s):  
Ionic Liquid ◽  
Carbon Paste Electrode ◽  
Sodium Dodecyl ◽  
Electrochemical Determination ◽  
Modified Carbon Paste Electrode ◽  
Oxidation Peak ◽  
Carbon Paste ◽  
Oxidation Peak Current ◽  
Paste Electrode

The electrochemical behavior and electrochemical determination of carbamazepine (CBZ) at hydrophobic ionic liquid 1-Benzyl-3-Methylimidazole hexafluorophosphate ([BnMIM]PF6) modified carbon paste electrode ([BnMIM]PF6/CPE) in the presence of sodium dodecyl sulfate (SDS) were investigated. A well-defined and sensitive oxidation peak was observed at [BnMIM]PF6/CPE in the presence of SDS and 0.10 M phosphate buffer solution (pH 6.80). The oxidation peak current of CBZ increased significantly at [BnMIM]PF6/CPE in the presence of SDS compared with that in the absence of SDS at carbon paste electrode. It suggested that both SDS and [BnMIM]PF6/CPE show an obvious enhancing effect on the electrochemical oxidation of CBZ. The electrochemical kinetic parameters for CBZ at [BnMIM]PF6/CPE in aqueous SDS solutions were also determined by Chronocoulometry and Chronoamperometry. Finally, the experimental conditions were optimized, and a new electrochemical method of determination for CBZ had been established. The oxidation peak current was linearly dependent on CBZ concentration in the range of 7.0 ?M to 0.7 mM with a detection limit of 0.98 ?M (signal to noice ratio, S/N = 3). The relative standard deviation for six determinations of 0.10 mM CBZ was between 1.40 and 2.13%. The proposed method was applied in the determination of CBZ in commercial tablet samples.

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 Sensitive Voltammetric Sensor for Tryptophan Detection by Using Polyvinylpyrrolidone Functionalized Graphene/GCE

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 125 ◽  
Author(s):  
Quanguo He ◽  
Jun Liu ◽  
Jinxia Feng ◽  
Yiyong Wu ◽  
Yaling Tian ◽  
...  
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Oxidation Mechanism ◽  
Carbon Electrode ◽  
Oxidation Peak ◽  
Experimental Conditions ◽  
Peak Current ◽  
Oxidation Peak Current

In this paper, an electrochemical method for the measurement of tryptophan (Trp) was developed based on a glassy carbon electrode modified with polyvinylpyrrolidonefunctionalized graphene (PVP-GR)/glassy carbon electrode (GCE). In 0.1 M phosphate buffer solution (PBS, pH = 2.2), compared with bare GCE, PVP/GCE, and GR/GCE, the oxidation peak current of Trp increased dramatically at PVP-GR/GCE. The oxidation mechanism of Trp on the PVP-GR/GCE was discussed and the experimental conditions were optimized. Under the best experimental conditions, the oxidation peak current of Trp was proportional to its concentration in the range of 0.06 µM–10.0 µM and 10.0–100.0 µM, and the limit of detection (LOD) was 0.01 µM (S/N = 3). The target modified electrode with excellent repeatability, stability and selectivity, was successfully applied to detectTrp in drugs and biological samples.

scholarly journals Electro-oxidation of formoterol fumarate on the surface of novel poly(thiazole yellow-G) layered multi-walled carbon nanotube paste electrode

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
N. Hareesha ◽  
J. G. Manjunatha
Keyword(s):  
Carbon Nanotube ◽  
Active Sites ◽  
Oxidation Peak ◽  
Peak Potential ◽  
Peak Current ◽  
Multi Walled Carbon Nanotube ◽  
Carbon Nanotube Paste Electrode ◽  
Electro Oxidation ◽  
Paste Electrode ◽  
Formoterol Fumarate

AbstractThe current study explicates the electro-oxidation behavior of formoterol fumarate (FLFT) in the presence of uric acid (UA) on the surface of poly thiazole yellow-G (TY-G) layered multi-walled carbon nanotube paste electrode (MWCNTPE). The modified (Poly(TY-G)LMWCNTPE) and unmodified (MWCNTPE) electrode materials were characterized through electrochemical impedance spectroscopy (EIS), field emission scanning electron microscopy (FE-SEM), and cyclic voltammetry (CV) approaches. The characterization data confirms the good conducting and electrocatalytic nature with more electrochemical active sites on the Poly(TY-G)LMWCNTPE than MWCNTPE towards the FLFT analysis in the presence of UA. Poly(TY-G)LMWCNTPE easily separates the two drugs (FLFT and UA) even though they both have nearer oxidation peak potential. The electro-catalytic activity of the developed electrode is fast and clear for FLFT electro-oxidation in 0.2 M phosphate buffer (PB) of pH 6.5. The Poly(TY-G)LMWCNTPE offered a well-resolved peak with the highest electro-oxidation peak current at the peak potential of 0.538 V than MWCNTPE. The potential scan rate and oxidation peak growth time studies show the electrode reaction towards FLFT electro-oxidation is continued through a diffusion-controlled step. The variation of concentration of FLFT in the range from 0.2 to 1.5 µM (absence of UA) and 3.0 to 8.0 μM (presence of UA) provides a good linear relationship with increased peak current and a lower limit of detection (LOD) values of 0.0128 µM and 0.0129 µM, respectively. The prepared electrode gives a fine recovery for the detection of FLFT in the medicinal sample with acceptable repeatability, stability, and reproducibility.

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.

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