scholarly journals Electrochemical Detection of Dopamine at a Gold Electrode Modified with a Polypyrrole–Mesoporous Silica Molecular Sieves (MCM-48) Film

2018 ◽  
Vol 20 (1) ◽  
pp. 111 ◽  
Author(s):  
Izabela Zablocka ◽  
Monika Wysocka-Zolopa ◽  
Krzysztof Winkler
Keyword(s):  
Ascorbic Acid ◽  
Cyclic Voltammetry ◽  
Detection Limit ◽  
Modified Electrode ◽  
Electrochemical Detection ◽  
Molecular Sieves ◽  
Gold Electrode ◽  
Square Wave Voltammetry ◽  
Wave Voltammetry

A gold electrode modified with a polypyrrole–mesoporous silica molecular sieves (polypyrrole—MCM-48) nanostructure film was used for the electrochemical determination of small concentrations of dopamine (DA) by cyclic voltammetry and square-wave voltammetry techniques. This electrode showed good electrocatalytic activity for the oxidation of dopamine. The oxidation potential of dopamine was decreased significantly compared with that obtained at the bare gold electrode. The observed linear range for the determination of the dopamine concentration, without interferents through cyclic voltammetry measurements, was from 10 μM to 1.2 mM (R2 = 0.9989) for the gold electrode modified with the polypyrrole—MCM-48 nanostructure, with a detection limit of 2.5 μM. In the case of square-wave voltammetry, the linear range was 2–250 μM, with a correlation coefficient of 0.9996, and the detection limit was estimated to be 0.7 μM. The effects of interferents, such as ascorbic acid (AA) and uric acid (UA), on the electrochemical detection of dopamine were also examined. The modified electrode can successfully separate the oxidation potentials for ascorbic acid and dopamine, shifting the oxidation peak potential of ascorbic acid to a more positive potential, and significantly decreasing the peak current. The presence of ascorbic acid increased the sensitivity of dopamine determination at the modified electrode, and the detection limit was estimated to be 0.5 μM with 0.1 mM ascorbic acid to imitate physiological solutions. Additionally, studies showed that the presence of uric acid does not affect the electrochemical detection of dopamine. The modified electrode can be successfully applied for the quantitative analysis of dopamine both with and without interferents.

scholarly journals Simultaneous and selective electrochemical determination of hydroquinone, catechol and resorcinol at poly(1,5-diaminonaphthalene)/glassy carbon-modified electrode in different media

RSC Advances ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 6346-6355 ◽  
Author(s):  
Khalid Mahmoud Hassan ◽  
Abla Ahmed Hathoot ◽  
Mohamed Fathi Abo oura ◽  
Magdi Abdel Azzem
Keyword(s):  
Cyclic Voltammetry ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Square Wave Voltammetry ◽  
Electrochemical Determination ◽  
Electrochemical Behaviors ◽  
Square Wave ◽  
Wave Voltammetry ◽  
Glassy Carbon Modified Electrode

Electrochemical behaviors of hydroquinone, catechol and resorcinol were examined at poly(1,5-diaminonaphthalene)/glassy carbon-modified electrode by cyclic voltammetry, square wave voltammetry and chronoamperometry techniques in different media.

Electrochemical Preparation and Application of PEDOT/Ferrocene Modified Electrode

2015 ◽  
Vol 727-728 ◽  
pp. 61-64 ◽  
Author(s):  
Xin Fei Zhou ◽  
Yan Hui Song ◽  
Kun Yun He ◽  
Hai Tao Zheng ◽  
Shinichiro Suye
Keyword(s):  
Ascorbic Acid ◽  
Cyclic Voltammetry ◽  
Electron Microscope ◽  
Electrochemical Impedance Spectroscopy ◽  
Modified Electrode ◽  
Gold Electrode ◽  
Electrochemical Impedance ◽  
Electrochemical Preparation ◽  
Scanning Electron

A highly stable and sensitive electrochemical sensor was developed by electropolymerisation of poly (3, 4-ethylenedioxythiophene) (PEDOT) and ferrocene (Fc) on gold electrode for the determination of ascorbic acid (AA). The PEDOT/Fc composite film modified Au electrode was characterized by field emission scanning electron microscope，electrochemical impedance spectroscopy and cyclic voltammetry. Compared with bare electrode, the PEDOT/Fc modified electrode exhibited excellent electrocatalytic activity toward the oxidation of AA.

scholarly journals Electrochemical determination of ascorbic acid at p-phenylenediamine film-holes modified glassy carbon electrode

2015 ◽  
Vol 80 (9) ◽  
pp. 1161-1175 ◽  
Author(s):  
Bikila Olana ◽  
Shimeles Kitte ◽  
Tesfaye Soreta
Keyword(s):  
Ascorbic Acid ◽  
Detection Limit ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Linear Response ◽  
Modified Electrodes ◽  
Electrochemical Determination ◽  
Carbon Electrode

In this work the determination of ascorbic acid (AA) at glassy carbon electrode (GCE) modified with a perforated film produced by reduction of diazonium generated in situ from p-phenylenediamine (PD) is reported. Holes were intentionally created in the modifier film by stripping a pre-deposited gold nanoparticles. The modified electrodes were electrochemically characterized by common redox probes: hydroquinone, ferrocyanide and hexamineruthenium(III). The cyclic voltammetric and amperometric response of AA using the modified electrodes was compared with that of bare GCE. The bare GCE showed a linear response to AA in the concentration range of 5 mM to 45 mM with detection limit of 1.656 mM and the modified GCE showed a linear response to AA in the concentration range of 5 ?M to 45 ?M with detection limit of 0.123 ?M. The effect of potential intereferents on amperometric signal of AA at the modified GCE was examined and found to be minimal. The inter-electrode reproducibility, stability, and accuracy were determined. The modified electrode showed excellent inter-electrode reproducibility, accuracy and stability. The modified electrode reported is a promising candidate for use in electroanalysis of AA.

scholarly journals Determination of clopidogrel using square wave voltammetry at a gold electrode

2013 ◽  
Vol 78 (12) ◽  
pp. 2131-2140 ◽  
Author(s):  
Aleksandar Mladenovic ◽  
Vladislava Jovanovic ◽  
Slobodan Petrovic ◽  
Dusan Mijin ◽  
Sasa Drmanic ◽  
...  
Keyword(s):  
Gold Electrode ◽  
Square Wave Voltammetry ◽  
Pharmaceutical Preparation ◽  
Antiplatelet Agent ◽  
Hplc Method ◽  
Tablet Form ◽  
Square Wave ◽  
Wave Voltammetry ◽  
Anodic Stripping

The determination of clopidogrel, an antiplatelet agent, was performed at a gold electrode in pH 3.7 acetate buffer using cyclic voltammetry (CV) and square wave voltammetry (SWV). Each voltammogram is characterized by the well defined peak at approximately 1.0 V. The current of anodic stripping peak exhibits linear dependence on the clopidogrel concentration in a range from 317.89 mg cm-3 to 935.16 mg cm-3. The obtained linearity was applied to determine clopidogrel amount in the tablet form of pharmaceutical preparation (Plavix?). The results were compared to the UV spectrophotometric and HPLC method.

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