Attachment of DNA to the Carbon Fiber Microelectrode via Gold Nanoparticles for Simultaneous Determination of Dopamine and Serotonin

Abstract

A novel biochemical sensor was fabricated on a carbon fiber microelectrode, which consisted of an inner layer of electrodeposited gold nanoparticles, as a nano-array electrode, and an outer layer of electrodeposited calf thymus ds-DNA at +1.5 V vs. SCE. This modified electrode was characterized by X-ray photoelectron spectroscopy, scanning electron microscope, atomic force microscopy, cyclic voltammetry and differential pulse voltammetry (DPV). It was found that this electrochemical sensor exhibits a strong catalytic activity toward the oxidation of dopamine (DA), serotonin (5-HT) and ascorbic acid (AA), as a result of resolving the anodic voltammetric peaks of DA, 5-HT and AA into three welldefined peaks. Simutaneous DPV determination of DA and 5-HT can be achieved in the presence of 2000-fold AA. The modified electrode shows good sensitivity, selectivity and stability.

Simultaneous Determination of Dopamine, Serotonin and Ascorbic Acid at a Glassy Carbon Electrode Modified with Carbon-Spheres

“…Up to now, there are a few reports in the literature about the simultaneous determination of DA, 5-HT and AA which used different electrochemical methods and electrodes for their simultaneous determination. For example, various chemically modified electrodes including electrodeposited nanostructured platinum on Nafion-coated GCEs [13], poly( o -phenylenediamine)- and poly(phenosafranine)-modified GCEs [14,15], choline- and acetylcholine-modified GCEs [16], DNA-immobilized carbon fibre microelectrodes [17,18], solid carbon paste electrode modified with a nonionic polymer film [19], and carbon paste electrodes modified with iron(II) phthalocyanine complexes [20] have been reported for the simultaneous determination of DA, 5-HT and AA. A proposed methodology for the discrimination between DA and 5-HT in the presence of AA with the combination of a large amplitude/ high frequency voltage excitation and signal processing techniques [21] is also reported in the literature.…”

Simultaneous determination of neurotransmitters and a neuroprotector in human blood serum and urine samples using a diazonium grafted gold nanoparticle film electrode

“…5B) and the detection limit was 8.0 Â 10 À11 M (S/N ¼ 3) for DA. The observed linear range and lowest detection limit for DA at the electrode modied with an AP-AuNP lm were compared with previously reported modied electrodes [37][38][39][40][41] (Table 1). We also compared our results with those for polymer lm modied electrodes for the detection of DA.…”

“…36 A few reports have been published on DA sensors using AuNP composite lms. [37][38][39][40][41] However, the fabrication of these lms requires tedious procedures or a series of steps and the reproducibility and detection limits of these methods are poor. In addition, these ligands bonded with AuNPs undergo place exchange 42 and are easily displaced in the presence of competitive solvents and with changes in temperature and pH.…”

Carbon Fiber-based Microelectrodes and Microbiosensors

“…Using a labelled method, the covalently bound DNA deposition resulted in a 500 to 1000-fold increase in the effective surface area and similarly enlarged voltammetric response to Co(Phen) 3 3+ . In a label-free method, double-stranded DNA was attached to the carbon surface via gold nanoparticles and was aplied to determine dopamine, serotonine and ascorbic acid using cyclic or differential pulse voltammetry (Lu et al, 2004). Simultaneous differential pulse voltammetry determination of dopamine and serotonine could be achieved in the presence of 1 mM ascorbic acid.…”