Square-Wave Voltammetric Detection of Dopamine at a Copper-(3-Mercaptopropyl) Trimethoxy Silane Complex Modified Electrode

Abstract

Square-wave voltammetric detection of dopamine was studied at a copper (Cu)-(3-mercaptopropyl) trimethoxy silane (MPS)-complex modified electrode (Cu-MPS). The modification of the electrode was based on the attachment of MPS onto an electrochemically activated glassy carbon electrode (GCE) by the interaction between methoxy silane groups of MPS and surface hydroxyl groups and followed by the complexation of copper with the thiol groups of MPS. The surface of the modified electrode was further coated by a thin layer of Nafion film. The surface of the Nafion coated MPS-Cu complex modified electrode (Nafion/Cu-MPS) was characterized using cyclic voltammetry, electrochemical quartz crystal microbalance (EQCM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT-IR) spectrometry. The modified electrode exhibited an excellent electrocatalytic activity towards the oxidation of dopamine, which was oxidized at a reduced potential of þ 0.35 V (vs. Ag/AgCl) at a wider pH range. Various experimental parameters, such as the amount of copper, the pH, and the temperature were optimized. A linear calibration plot was obtained in the concentration range between 8.0 Â 10 À8 M and 5.0 Â 10 À6 M and the detection limit was determined to be 5.0 Â 10 À8 M. The other common biological compounds including ascorbic acid did not interfere and the modified electrode showed an excellent specificity to the detection of dopamine. The Nafion/Cu-MPS modified electrode can be used for about 2 months without any significant loss in sensitivity.

Recent Advances in Electrochemical and Optical Sensing of Dopamine

“…Copper (Cu)-(3-mercaptopropyl) trimethoxy silane (MPS)-complex modified electrode (Cu-MPS) was successfully developed to detect DA [209]. Nafion thin film was coated on the surface of the modified electrode and contributed to neglect the signals related to other biological species.…”

Selective determination of dopamine with a cibacron blue/poly-1,5-diaminonaphthalene composite film

“…To date, composite polymer films were prepared with the precursors of conductive polymer, aniline/aniline sulfonic acid and ethylenedioxythiophene/aminonaphthalenesulfonic acid in order to introduce sulfonate groups in the polymer film [26,27]. Generally, charge-selective electrochemical detection of DA has been carried out using Nafion coated electrodes to avoid interference of AA [16,17]. However, a disadvantage of this method is the sensitivity of the modifier towards DA reduced by Nafion layer coating.…”

“…: +82 51 510 2244; fax: +82 51 514 2430. ids proceeds as a two-electron process, forming catecholamine o-quinones that can catalytically oxidize AA to regenerate DA, resulting in an increase in the oxidation signal of DA [9]. To solve these problems and enhance selectivity and sensitivity of the electroanalytical methods for DA, several kinds of electrode modification techniques have been developed [10][11][12][13][14][15][16][17]. Although some research has achieved success in this direction, it still demands much effort to develop a simple, selective, and sensitive method for DA detection.…”

Characterization of O+ Ion‐implanted Glassy Carbon Using the Superconducting Electron Cyclotron Resonance Ion Source and Selective Dopamine Detection

“…Therefore, it is crucial to develop sensitive and selective methods especially for detecting low concentration of DA. There are several DA detection methods including electrochemical sensors [19–21]. Of them, various amperometric sensors were developed through incorporating of modifiers on the electrode surface [22, 23].…”