Selective and Simultaneous Voltammetric Determination of Glutathione, Uric Acid and Penicillamine by a Modified Carbon Nanotube Paste Electrode

Abstract

In this paper, the use of a carbon paste electrode (CPE) modified by (E)‐3‐((2‐(2,4‐dinitrophenyl)hydrazono)methyl)benzene‐1,2‐diol (DHB) and carbon nanotubes (CNTs) for the determination of glutathione (GSH), uric acid (UA) and penicillamine (PA) is described. Initially, cyclic voltammetry was used to investigate the redox properties of the modified electrode in phosphate buffer. Next, the electrocatalytic oxidation of GSH via EC′ mechanism at the modified electrode was described. At the optimum pH of 7.0, the oxidation of GSH occurs at a potential that is 530 mV less positive than that of an unmodified carbon paste electrode. The values of the diffusion coefficient (D=2.5×10−6 cm2 s−1) and the catalytic rate constant (k=1.7×103 M−1 s−1) were calculated for GSH, using chronoamperometry. Based on differential pulse voltammetry, the oxidation of GSH exhibited a dynamic range between 0.4 and 700.0 µM and a detection limit (3σ) of 70.0 nM. Also, simultaneous determination of GSH, UA and PA was described at the modified electrode. Finally, this method was used for the determination of these substances in synthetic solutions and blood serum samples.

A Review on the Effects of Introducing CNTs in the Modification Process of Electrochemical Sensors

“…The peak potential separation was determined 240 mV for the oxidation of glutathione and uric acid, and 290 mV for uric acid and penicillamine [36]. The CV results demonstrated no anodic and cathodic peaks for unmodified CPE in phosphate buffer, however; after the modification, the peak potentials of 0.220 V (anodic) and 0.165 V (cathodic) appeared related to oxidation and reduction of hydroquinone derivative.…”

A Sensitive Voltammetric Sensor for Determination of Glutathione Based on Multiwall Carbon Nanotubes Paste Electrode Incorporating Pyrogallol Red

“…Several methods have been reported for the determination of GSH. These, include chemiluminescence 18 , High Performance Liquid Chromatography (HPLC) [19][20][21] , capillary electrophores [22][23][24][25][26] , derivatization methods 27 , liquid chromatography-tandem mass spectrometry (LC-MS/MS) 28 , liquid chromatography -electrospray mass spectrometric (HPLC-ESI-MS) 29 , liquid chromatography-Electrochemical Method [30][31][32] , Electrochemical methods provide useful alternatives since they allow faster, cheaper and safer analysis [33][34][35][36][37][38][39][40] .…”

A simple method for determination of d-penicillamine on the carbon paste electrode using cupric ions

“…Some of these methods include colorimetry , fluorimetry [5], chromatography [6], flow injection analysis [7], electrophoresis [8], potentiometry [9], voltammetry [10,11], PMR spectrometry [12] and NMR spectrometry [13].…”