Simultaneous Determination of Ascorbic Acid, Dopamine and Uric Acid at Pt Nanoparticles Decorated Multiwall Carbon Nanotubes Modified GCE

Abstract

A modified electrode was fabricated by electrochemically deposition of Pt nanoparticles on the multiwall carbon nanotube covered glassy carbon electrode (Pt nanoparticles decorated MWCNT/GCE). A higher catalytic activity was obtained to electrocatalytic oxidation of ascorbic acid, dopamine, and uric acid due to the enhanced peak current and well-defined peak separations compared with both, bare and MWCNT/GCE. The electrode surfaces were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrochemical impedance spectroscopy (EIS). Individual and simultaneous determination of AA, DA, and UA were studied by differential pulse voltammetry. The detection limits were individually calculated for ascorbic acid, dopamine, and uric acid as being 1.9 Â 10 À5 M, 2.78 Â 10 À8 M, and 3.2 Â 10 À8 M, respectively. In simultaneous determination, LODs were calculated for AA, DA, and UA, as of 2 Â 10 À5 M, 4.83 Â 10 À8 M, and 3.5 Â 10 À7 M, respectively.

Synthesis of graphene/methylene blue/gold nanoparticles composites based on simultaneous green reduction, in situ growth and self-catalysis

“…Preliminary experiments were carried out to explore the application of the rGO/MB/AuNPs composites modified electrode for the determination of AA, DA, and UA. Compared with previously reported nano-structured materials modified electrodes [54][55][56][57], the rGO/MB/AuNPs composites modified electrode presents a lower detection limit (2.5, 0.15, and 0.25 lmol L -1 for AA, DA, and UA, respectively) because of the excellent electrochemical properties of this proposed rGO/MB/AuNPs composites.…”

Electrochemical Determination of Dopamine Based on Carbon Nanotube-Sol-Gel Titania-Nafion Composite Film Modified Electrode

“…As summarized in Table 1, the present DA sensor based on the CNT-titania-Nafion/GC electrode displayed a relatively low detection limit even without the additional loading of noble metal NPs such as Pt, Au and Pd [11][12][13][14] or a complicated CNT modification step. [18][19][20] However, the present sensor showed a relatively wide linear dynamic range from 0.5 μM to 500 μM. Moreover, the present DA sensor based on the CNT-titania-Nafion/GC electrode exhibited relatively fast response time less than about 2.0 s, which is much faster than those at the CNT-Nafion composite film (4.6 s) and titaniaNafion composite film (2.4 s) as shown in the current-time response profile (Figure 5, inset).…”

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] These include pretreatment and modification of electrode surface with various materials such as self-assembled monolayers, 4,5 permselective film coatings such as Nafion 6 and electropolymerized polymer, 7 zeolite, 2 cyclodextrins, 8 and DNA. 9 Because of the excellent electrocatalytic activity of noble metal nanoparticles (NPs), [11][12][13][14] carbon based nano-materials such as nanofiber, 15 graphene, 17 and nanotube, 10,[18][19][20] the DA sensors based on these nano-materials exhibited good sensitivity and stability. Despite of these great advantages of those carbonbased nano-materials, the insolubility of them, especially carbon nanotube (CNT), in most solvents is one of the most difficult obstacles for their wide application in electrochemical sensors.…”

Determination of ascorbic acid levels in food samples by using an ionic liquid–carbon nanotube composite electrode

“…Generally, the direct detection of AA can be achieved by the oxidation at a high potential (+0.38 V versus Ag/AgCl) at the glassy carbon electrode. However, some other electroactive species which are usually present in biological fluids, such as uric acid and dopamine, can also be oxidised at that potential and produce an interfering current (Dursun & Gelmez, 2010). Moreover, the oxidation product of AA, dehydroascorbic acid (DHA), can be strongly adsorbed onto the electrode surface, which results in electrode fouling and poor reproducibility (Salimi, MamKhezri, & Hallaj, 2006).…”