Electrochemical dopamine sensor using a nanoporous gold microelectrode: a proof-of-concept study for the detection of dopamine release by scanning electrochemical microscopy

Abstract

Nanoporous gold (NPG) structures were prepared on the surface of a gold microelectrode (Au-μE) by an anodization-reduction method. Cyclic voltammetry and field emission scanning electron microscopy were used to study the electrochemical properties and the morphology of the nanostructured film. Voltammetry showed an improved sensitivity for dopamine (DA) oxidation at this microelectrode when compared to a bare gold microelectrode, with a peak near 0.2 V (vs. Ag/AgCl) at a scan rate of 0.1 V s. This is due to the increased surface area and roughness. Square wave voltammetry shows a response that is linear in the 0.1-10 μmol L DA concentration range, with a 30 nmol L detection limit and a sensitivity of 1.18 mA (μmol L) cm. The sensor is not interfered by ascorbic acid. The reproducibility, repeatability, long-term stability and real sample analysis (spiked urine) were assessed, and acceptable performance was achieved. The "proof-of-concept" detection of dopamine release was demonstrated by using scanning electrochemical microscopy (SECM) with the aim of future applications for single cell analysis. Graphical abstract A reproducible electrochemical approach was proposed to fabricate an NPG-microelectrode for DA detection, with enhanced sensitivity and selectivity. Besides, a proof-of-concept detection of DA release was also demonstrated by using SECM.

CeO2-Based Two-Dimensional Layered Nanocomposites Derived from a Metal–Organic Framework for Selective Electrochemical Dopamine Sensors

“…They exhibited a correlation coefficient of 0.9915 and 0.9812, respectively ( Figure 6 c). This result confirms that DA’s oxidation behavior with the CeO 2 /siloxene/GCE electrode is an adsorption-controlled process [ 39 ].…”

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] …”

Nanomaterials-Based Electrochemical Sensors for In Vitro and In Vivo Analyses of Neurotransmitters

“…Scanning electrochemical microscopy (SECM) is also another important technique that has been used to detect and monitor neurotransmitters. For instance, dopamine released from single cells was successfully monitored using SECM [9].…”

“…A variety of nanomaterials have been explored for the electrochemical detection of neurochemicals, as illustrated in Figure 1. For instance, noble metals (e.g., Au, Ag, Pt, and Pd), non-noble metal oxides (e.g., Fe 2 O 3 , FeMoO 4 , NiO, and Co 3 O 4 ), polymers (e.g., polypyrrole, Nafion, and poly(3,4ethylenedioxythiophene) (PEDOT)), carbon-based nanomaterials (carbon nanotubes (CNT), graphene, and carbon fiber), and the combination of these materials have been used for in vitro and/or in vivo detection of neurotransmitters [9][10][11][12]. The size, shape, and synthetic procedure of the functional nanomaterials may considerably influence the sensing performance.…”