Interference-Free Determination of Dopamine at the Poly(thionine)-Modified Glassy Carbon Electrode

Abstract

A highly selective and sensitive electrochemical method, based on a poly(thionine)-modified glassy carbon electrode (PTH-GCE), was developed for the determination of dopamine (DA). The modified electrode was characterized by electrochemical techniques and an atomic force microscope (AFM). The modified GCE exhibited catalytic behavior towards the oxidation of DA in 0.1 M pH 7.0 phosphate buffer solution (PBS). In differential pulse voltammetry (DPV) measurements, the oxidation peak potential of ascorbic acid (AA), uric acid (UA) and serotonin (5-HT) overlapped with that of DA at the bare GCE. However, the oxidation peak of 5-HT was separated from that of DA at the PTH-GCE while the oxidation of AA and UA were suppressed at the same time. The peak potential separation of ca. 0.2 V was large enough for selective determination of DA from the interference of 5-HT. A linear range of 5.0–35.0 μM and a detection limit (S/N = 3) of 0.2 μM were obtained for DA detection in PBS (pH 7.0). This approach provides a simple and easy method to detect DA selectively from the interferences of AA, UA and 5-HT.

Individual and Simultaneous Voltammetric Determination of Ultra-Trace Environmental Contaminant Dihydroxybenzene Isomers Based on a Composite Electrode Sandwich-like Structure

“… 10 However, electroanalytical techniques have attracted further attention because of its superior advantages of low cost, real-time results, high accuracy and stability, small sample size, and environmentally friendliness. 11 It has been reported that the bare electrode surface modified by a thin coat of the organic polymer has got much attention because of its versatile characteristics of enhancing the electrode performance and utilization of the electrocatalytic methods on different unique applications. 12 Our research group has recently reported the individual and simultaneous determination of CC, HQ, and RS on poly(1,5-diaminonaphthalene) (DAN)/glassy carbon electrode (GCE)-modified electrode.…”

Simultaneous Detection and Estimation of Catechol, Hydroquinone, and Resorcinol in Binary and Ternary Mixtures Using Electrochemical Techniques

“…Many analytical methods have been established to determine dihydroxybenzene isomers, such as HPLC [ 8 ], fluorescence [ 9 ], chemiluminescence [ 10 ], spectrophotometry [ 11 ], GC-MS [ 12 ], and electrochromatography [ 13 ]. Among them, electrochemical methods have attracted ever-growing attention due to the advantages such as fast response, low cost, simple operation, faster analysis, high sensitivity, and excellent selectivity [ 14 ]. At ordinary bare electrodes, these isomers show highly overlapping voltammograms where their redox peaks are not resolved [ 15 – 20 ].…”

Hydrogen Peroxide Biosensors Based on Horseradish Peroxidase and Hemoglobin

“…Several methods, such as titrimetry [3], spectrometry [4], chemiluminescence [5], fluorimetry [6], chromatography [7], and electrochemical techniques [8,9], have been reported for this purpose. Among these techniques, the electrochemical techniques are preferable because of their simplicity, low cost, high sensitivity, and selectivity [10][11][12][13][14][15][16]. In particular, an amperometric biosensor is an attractive tool for the detection of H 2 O 2 .…”