Differential Electroanalysis of Dopamine in the Presence of a Large Excess of Ascorbic Acid at a Nickel Oxide Nanoparticle-Modified Glassy Carbon Electrode

Zahrah T Althagafi,Jalal T Althakafy,Mohamed I Awad,Badriah A Al Jahdaly

doi:10.1155/2020/8873930

Zahrah T Althagafi, Jalal T Althakafy + Show 2 more

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https://doi.org/10.1155/2020/8873930

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Abstract

Electrochemical determination of dopamine (DA) in the presence of a large excess of ascorbic acid (AA) in their coexistence at a nickel oxide nanoparticle-modified preoxidized glassy carbon electrode (GCox/nano-NiOx) is achieved. The GCox/nano-NiOx electrode is prepared by electrodeposition of nickel nanoparticles (nano-Ni) onto an electrochemically activated glassy carbon (GC) electrode, and the thus prepared nano-Ni were subjected to electrochemical oxidation in alkaline medium for the formation of nickel oxide (NiOx). Modified electrodes were electrochemically and morphologically characterized. The effect of loading level of nickel was investigated by changing the number of potential cycles for the deposition of nano-Ni, i.e., 1, 2, 5, and 10 potential cycles, in the potential range from 0 to -1.0 V vs. SCE. Also, the experimental and instrumental parameters were optimized. Experimental results showed that the modified electrode differentiates well the oxidation peaks of DA and AA enabling the electrochemical determination of DA in the presence of a large excess of AA. Remarkably, it is found that the oxidation current of DA is 2 times larger than that of AA even the concentration of AA is about 5 times larger than that of DA. The LOD and LOQ of DA were calculated and were found to equal 0.69 and 2.3 mM, respectively. This offers the advantage of simple and selective detection of DA free of the interference of AA in real samples.

Highlights

Dopamine (DA) is critical for medical treatment and clinical analysis
The purpose of this work is to investigate the electroanalysis of DA in the presence of overly abundant ascorbic acid (AA) at the glassy carbon (GC) electrode modified with nano-nickel oxide (NiOx) by cyclic and square wave voltammetries
Typical EDX, SEM, and X-ray diffraction (XRD) micrographs obtained on the surface of the bare GC, GCox, and GCox/nano-NiOx electrodes are presented in Figures 1–3, respectively

Summary

Introduction

Dopamine (DA) is critical for medical treatment and clinical analysis. DA has long been of interest to neuroscientists and chemists because of its role as an essential neurotransmitter in the functionality of the central nervous, renal, hormonal, and cardiovascular systems [1]. A major problem for the detection of DA is the coexistence of many interfering compounds in biological systems. AA is a vital vitamin in the diet of humans, and it has been used for the prevention and treatment of common cold, mental illness, and other diseases [6]. To quantify DA coexisting with a large excess of AA, the major challenge is to achieve both high selectivity and sensitivity of the detection technique

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