A glassy carbon electrode modified with MoS2 nanosheets and poly(3,4-ethylenedioxythiophene) for simultaneous electrochemical detection of ascorbic acid, dopamine and uric acid

Abstract

We describe a chemical exfoliation method for the preparation of MoS 2 nanosheets. The nanosheets were incorporated into poly(3,4-ethylenedioxythiophene) (PEDOT) by electrodeposition on a glassy carbon electrode (GCE) to form a nanocomposite. The modified GCE is shown to enable simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Due to the synergistic effect of MoS 2 and PEDOT, this electrode displays better properties in terms of electrocatalytic oxidation of AA, DA and UA than pure PEDOT, which is illustrated by cyclic voltammetry and differential pulse voltammetry (DPV). Under optimum conditions and at pH 7.4, the respective sensitivities and best working potentials are as follows: AA: 1.20 A mM −1 m −2 , 30 mV; DA: 36.40 A mM −1 m −2 , 210 mV; UA: 105.17 A mM −1 m −2 , 350 mV. The calculated detection limits for AA, DA and UA are 5.83 μM, 0.52 μM and 0.95 μM, respectively. The modified electrode was applied to the detection of the three species in human urine samples and gave satisfactory results.

Sol-Gel Mediated Greener Synthesis of γ-Fe2O3 Nanostructures for the Selective and Sensitive Determination of Uric Acid and Dopamine

“…The γ-Fe 2 O 3 nanostructures modified GCE were attained by coating 5 µL of the resultant suspension at the surface of the polished GCE, followed by drying at ambient temperature. Finally, the γ-Fe 2 O 3 nanostructures/GCE was operated in 0.1 M Phosphate buffer solution (PBS) at pH 7.4 by consecutive cyclic scans at an applied voltage between -0.2 and +0.8 V [32]. At each experimental set up, the nanostructures modified GC electrode was cleansed with water and reactivated in PBS as discussed earlier.…”

Fabrication of Au Nanoparticle-Decorated MoS2 Nanoslices as Efficient Electrocatalysts for Electrochemical Detection of Dopamine

“…Of the various methods of DA determination [2,5,6], the electrochemical sensor is preferred due to its fast response, high sensitivity, good selectivity, and low cost [7,8]. In order to get better response signals, various nanomaterials or nanocomposites have been used as electrocatalysts towards the oxidation of DA, such as carbon-based nanomaterials, noble metal nanoparticles [9], and conducting polymers [3,[10][11][12]. Among these materials, two-dimensional (2D) nanomaterials or their corresponding composites play major roles.…”

Carbon Black-Carbon Nanotube Co-Doped Polyimide Sensors for Simultaneous Determination of Ascorbic Acid, Uric Acid, and Dopamine

“…However, UA, AA, and DA always coexist in real biological samples. In addition, they show nearly the same oxidation potential on traditional electrodes [ 9 ]. Therefore, the development of a selective method for the simultaneous detection of the mixture is highly desirable [ 10 ].…”