Voltammetric Peak Separation of Dopamine from Uric Acid in the Presence of Ascorbic Acid at Greater Than Ambient Solution Temperatures

Abstract

Peak overlap in voltammetry poses challenges for the quantitative analysis of electroactive species. Dopamine and uric acid are typically challenging to determine voltammetrically because of their very similar oxidation peak potentials. We report preliminary results of the use of a screen-printed carbon electrode for the determination of dopamine and uric acid in an electrolyte solution maintained above ambient temperatures. Higher temperatures resulted in dramatic shifting of the dopamine oxidation peak toward lower potentials, while the uric acid peak was essentially stationary. Ascorbic acid, an interference in voltammetric uric acid determinations, is effectively suppressed at higher temperatures. This resulted in a greater peak separation of dopamine from uric acid at higher temperatures, which is desirable for better peak integration. In addition, greater current responses for both species were recorded at higher temperatures. The cause for such an increase in peak current is unraveled using ac impedance measurements. Presented are preliminary results for determining dopamine and uric acid at temperatures higher than ambient. Much improved voltammetric peak separation and sensitivity is obtained at these higher temperatures compared to ambient.

Controlled chemistry of tailored graphene nanoribbons for electrochemistry: a rational approach to optimizing molecule detection

“…Characterization of the graphene nanoribbons 35 The structures and morphologies of the graphene samples were characterized using AFM, as shown in Fig. 1.…”

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“…In the bibliography interactions between molecules and graphene have been reported using density functional theory and quantum physics 39,40 . The studies described here sought to (1) 35 explore the electrochemical performances of fully characterized GNRs with respect to the detection of significant target molecules, and (2) …”

Selective response of dopamine in the presence of ascorbic acid and uric acid at gold nanoparticles and multi-walled carbon nanotubes grafted with ethylene diamine tetraacetic acid modified electrode

“…Design and development of a simple and rapid detection method for dopamine (DA), an important neurotransmitter in mammalian central nervous system [1,2] has drawn much attention [3][4][5][6]. In real biological matrices, the concentration of DA is very low, while many coexisting substances such as ascorbic acid (AA) are in relatively high, 1000 times higher than that of DA generally.…”

Simultaneous Voltammetric Determination of Ascorbic Acid, Dopamine and Uric Acid Using Polybromothymol Blue Film-Modified Glassy Carbon Electrode

“…8) Various approaches have been attempted to solve the problems encountered in the simultaneous determination of AA, DA, and UA. [9][10][11][12][13][14][15][16] For example, Multi-Wall Carbon Nanotubes (MWNT)s-ionic liquid gel-modified electrodes have been used to detect DA in the presence of AA and UA with satisfactory results. The voltametric peaks corresponding to these three species were separated by ca.…”