Simultaneous Determination of Dopamine and Ascorbic Acid Using the Nano‐Gold Self‐Assembled Glassy Carbon Electrode

Abstract

Electrochemical behavior of dopamine (DA) was investigated at the gold nanoparticles self-assembled glassy carbon electrode (GNP/LC/GCE), which was fabricated by self-assembling gold nanoparticles on the surface of l-cysteine (LC) modified glassy carbon electrode (GCE) via successive cyclic voltammetry (CV). A pair of well-defined redox peaks of DA on the GNP/LC/GCE was obtained at E pa ¼ 0.197 V and E pc ¼ 0.146 V, respectively. And the peak separation between DA and AA is about 0.2 V, which is enough for simultaneous determination of DA and AA. The peak currents of DA and AA were proportional with their concentrations in the range of 6.0 Â 10, with the detection limit of 2.0 Â 10 À8 mol L À1 and 3.0 Â 10 À7 mol L À1 (S/N ¼ 3), respectively. The modified electrode exhibits an excellent reproducibility, sensibility and stability for simultaneous determination of DA and AA in human serum with satisfactory result.

Selective determination of L-dopa in the presence of uric acid and ascorbic acid at a gold nanoparticle self-assembled carbon nanotube-modified pyrolytic graphite electrode

“…It is a fact that gold nanoparticles show good electrocatalytic activity towards the electrochemical oxidation of dopamine [31][32][33]. In this paper, we have synthesized gold nanoparticlefunctionalized multi-wall carbon nanotubes by a self-assembly method.…”

Gold nanoparticle based optical and electrochemical sensing of dopamine

“…For the purpose of enhancing the sensing performance especially increasing its selectivity and reproducibility, they have used the self-assembled monolayers technique (SAM) to immobilized AuNPs on an amine-terminated monolayer of cystamine (CYST) on a polycrystalline gold electrode. This CYST monolayer/AuNPs modified Au electrode shows a well separation between the voltammetry signals of AA and DA associated to the existence of negatively charged SAM which has modifying the surface of electrode in order to differentiate DA from AA [41]. The negatively charged SAM act as a selective reagent which selective to the oppositely charged analyte, thus helps to separate the voltammetry signals of DA and AA.…”

Electrocatalytical Oxidation of Nitrite and Its Determination Based on Au@Fe3O4 Nanoparticles

“…This procedure is similar to the previous reports [19,20]. Next, the electrode was rinsed with ethanol and double-distilled water to remove unreacted species from its surface and was later immersed in Au@Fe 3 O 4 solution for 6 h at 4 8C to fabricate the Au@Fe 3 O 4 /Cys/GCE.…”