Investigation of Carbon Allotropes for Simultaneous Determination of Ascorbic Acid, Epinephrine, Uric Acid, Nitrite and Xanthine

Abstract

In this study, modified glassy carbon electrode (GCE) with different carbon allotropes such as multiwall carbon nanotubes (MWCNTs), graphene, bucky ball and graphite have been used for the simultaneous determination of ascorbic acid (AA), epinephrine (EP), uric acid (UA), Nitrite (NO 2 -), and xanthine (XN). Different electrochemical methods such as cyclic voltammetry, differential pulse voltammetry and chronoamperometry methods were employed to study the behavior of AA, EP, UA, NO 2 -and XN on these proposed modified electrodes. The modified GCE with MWCNTs was successfully used for simultaneous determination of AA, EP, UA, NO 2 -and XN. The electron transfer coefficients, diffusion coefficients and standard heterogeneous rate constant were determined for the electrochemical oxidation of AA, EP, UA, NO 2 -and XN. Under the optimum conditions, detection limits of 16.3, 3.92, 0.37, 29.9 and 0.13 µM were obtained for AA, EP, UA, NO 2 -, and XN, respectively. Moreover, the best modified GCE was applied for simultaneous determination of AA, EP, UA, NO 2 -, and XN in Human urine, serum and AA Tables samples.

Simultaneous Determination of Four DNA bases at Graphene Oxide/Multi-Walled Carbon Nanotube Nanocomposite-Modified Electrode

“…These experimental results matched with previous literature records [11,22,28,[31][32][33][34]. As shown in the reaction scheme (1)-(3) and (5) of Scheme 2, two protons and two electrons were postulated to be involved in rate determining steps of electrochemical oxidations of UA G, A, and C [11,22,31,32,34]. While for oxidation of T, only one electron and one proton were involved (reaction scheme (4), Scheme 2) [35].…”

“…The slopes for plots of E p vs. pH were 62.5, 56.1, 60.1, 58.2, and 52.7 mV/pH for UA, G, A, T and C, respectively. All these values were close to the Nernstian theoretical value of 59.1 mV/pH which indicated that there was an equal number of protons and electrons exchanged for each analyte in the electrochemical oxidation mechanisms [31]. These experimental results matched with previous literature records [11,22,28,[31][32][33][34].…”

“…All these values were close to the Nernstian theoretical value of 59.1 mV/pH which indicated that there was an equal number of protons and electrons exchanged for each analyte in the electrochemical oxidation mechanisms [31]. These experimental results matched with previous literature records [11,22,28,[31][32][33][34]. As shown in the reaction scheme (1)-(3) and (5) of Scheme 2, two protons and two electrons were postulated to be involved in rate determining steps of electrochemical oxidations of UA G, A, and C [11,22,31,32,34].…”

Chemically synthesized chevron-like graphene nanoribbons for electrochemical sensors development: determination of epinephrine

“…The detection (LOD) and quantification limits (LOQ) values for the DPV detection of EPI, obtained as the ratio between three and ten times the standard deviation of the blank signal and the sensitivity, were found to be 2.1 µM and 6.4 µM, respectively. In Supplementary Table S2, the LOD and linearity range of several electrochemical methods found in the literature for EPI determination are compared with our method [54][55][56][57][58][59][60][61][62][63][64][65][66][67] . As it can be observed, the developed sensor shows good analytical properties similar to those obtained for others also based on nanomaterials.…”

Development of a novel electrochemical nitrite sensor based on Zn‐Schiff base complexes

“…[29,30] The electrochemical behavior of nitrites on the surfaces of conventional solid electrodes was investigated by using various methods and sensing materials. [31][32][33] Sensitivity and selectivity are two major factors whose improvements have been always an active in the electrochemical sensor field. Improving the sensitivity and selectivity of sensors has always been a critical concern for researchers to improve the sensors performance and push them forward to practical application.…”