Electrochemical Detection of Dopamine at a Gold Electrode Modified with a Polypyrrole–Mesoporous Silica Molecular Sieves (MCM-48) Film

Abstract

A gold electrode modified with a polypyrrole–mesoporous silica molecular sieves (polypyrrole—MCM-48) nanostructure film was used for the electrochemical determination of small concentrations of dopamine (DA) by cyclic voltammetry and square-wave voltammetry techniques. This electrode showed good electrocatalytic activity for the oxidation of dopamine. The oxidation potential of dopamine was decreased significantly compared with that obtained at the bare gold electrode. The observed linear range for the determination of the dopamine concentration, without interferents through cyclic voltammetry measurements, was from 10 μM to 1.2 mM (R2 = 0.9989) for the gold electrode modified with the polypyrrole—MCM-48 nanostructure, with a detection limit of 2.5 μM. In the case of square-wave voltammetry, the linear range was 2–250 μM, with a correlation coefficient of 0.9996, and the detection limit was estimated to be 0.7 μM. The effects of interferents, such as ascorbic acid (AA) and uric acid (UA), on the electrochemical detection of dopamine were also examined. The modified electrode can successfully separate the oxidation potentials for ascorbic acid and dopamine, shifting the oxidation peak potential of ascorbic acid to a more positive potential, and significantly decreasing the peak current. The presence of ascorbic acid increased the sensitivity of dopamine determination at the modified electrode, and the detection limit was estimated to be 0.5 μM with 0.1 mM ascorbic acid to imitate physiological solutions. Additionally, studies showed that the presence of uric acid does not affect the electrochemical detection of dopamine. The modified electrode can be successfully applied for the quantitative analysis of dopamine both with and without interferents.

Electrochemical Detection of Dopamine Based on Functionalized Electrodes

“…Most of these techniques use carbon-based electrodes because of their advantages for biological applications [24]. For example, graphene electrodes functionalized with porphyrin [25], graphene oxide/multiwalled carbon nanotubes functionalized with hexadecyl trimethyl ammonium bromide [26], gold electrodes modified with polypyrrole-mesoporous silica molecular sieves [27], carbon quantum dot modified electrodes [6], reduced graphene oxide/polyethylenimine on a gold microelectrode [7], manganese tetraphenylporphyrin/reduced graphene oxide nanocomposite [8], or pretreated screen-printed carbon electrodes with NaOH [9] allow users to reach a limit of detection for dopamine from 1 µM to 8 nM (see Table S1, Supplementary Materials). Our system favors selectivity optimization, and functionalization with recognition molecules in conjunction with gold nanoparticles can be beneficial for designing multiplexed sensors.…”

Disposable Capacitive Biosensor for Dopamine Sensing

“…The prepared Tyr biosensor showed good detection performance towards dopamine compared to previously reported sensors and biosensors (Table 1). [13–32] …”

“…A detailed discussion of Tyr catalyzed dopamine oxidation reaction has been provided in later sections. Several kinds of functionalized electrochemical sensors [24–30] and biosensors [31,32] were also reported for dopamine screening, however, the detection limits of fabricated electrodes were found to be high (Table 1). [13–32] …”

Electrochemical Detection of Dopamine at Fe3O4/SPEEK Modified Electrode

“…Different assays such as chromatography [ 15 , 16 ], chemiluminescence [ 17 ], fluorescence [ 18 ], and electrochemistry [ 19 , 20 , 21 , 22 ] is employed for DA detection. The use of electrochemistry has found wide attraction among the various methods owing to high selectivity, sensitivity, simple instrumentation with a fast response, and cost-effectiveness [ 19 , 20 , 21 , 22 ].…”