Selective Electrochemical Detection Of Dopamine Research Articles

Eco-friendly Synthesis of Gold Nanoparticles by Using B. javanica Blume Leaves Extract Encapsulated with Graphene Oxide for Selective Electrochemical Detection of Dopamine

Eco-friendly Synthesis of Gold Nanoparticles by Using B. javanica Blume Leaves Extract Encapsulated with Graphene Oxide for Selective Electrochemical Detection of Dopamine

Au nanoparticles anchored on Ni(OH)2 nanowires with multiple cavities for selective electrochemical detection of dopamine

Au nanoparticles supported on nickel hydroxide nanowires with multiple cavities (Au/m-Ni(OH)2) were synthesized and used for the enhanced electrochemical sensing of dopamine (DA).

Watsonia meriana flower like Fe3O4/reduced graphene oxide nanocomposite for the highly sensitive and selective electrochemical sensing of dopamine

This work reports the design and development of iron oxide (Fe3O4)/graphene nanocomposite for the highly sensitive and selective electrochemical detection of dopamine (DA). The decoration of graphene sheets with Fe3O4 nanostructures was achieved by a simple process of one-step chemical reaction strategy. The morphological studies revealed the six petalled Watsonia meriana flower like Fe3O4 nanostructures and the average length of each petal ranging from the centre is found to be 1.23 μm and the average diameter of nanoparticles that constitutes the petal is 30 nm and the plausible growth mechanism of above nanostructures was analyzed in detail. The cubic inverse spinel structure of prepared Fe3O4 nanomaterials was confirmed from the diffraction patterns and the morphology, size, and structure of bare Fe3O4 nanomaterials were not altered even after the composite formation with graphene. The catalytic activity of prepared nanostructures toward DA oxidation was investigated by the electrochemical techniques and Fe3O4/rGO nanocomposite exhibited an excellent electrocatalytic oxidation of DA with the amperometric current - time response of 5 s, a wide linear range between 0.010 and 0.270 μM, high sensitivity of 19.75 μA/μM.cm2 and a lower detection limit of 5 nM. The sensor has proven its superior selectivity toward the detection of DA even under the presence of biologically co-active interfering species and the application of constructed sensor in human urine sample was also successfully demonstrated, which guaranteed the real sample analysis of fabricated sensor with the high accuracy.

Selective electrochemical detection of dopamine in the presence of uric acid and ascorbic acid based on a composite film modified electrode

An electrochemical dopamine sensor based on vanadium-substituted polyoxometalates, copper oxide and chitosan–palladium was fabricated by the LBL technique.

Electrospun polyamide 6/poly(allylamine hydrochloride) nanofibers functionalized with carbon nanotubes for electrochemical detection of dopamine.

The use of nanomaterials as an electroactive medium has improved the performance of bio/chemical sensors, particularly when synergy is reached upon combining distinct materials. In this paper, we report on a novel architecture comprising electrospun polyamide 6/poly(allylamine hydrochloride) (PA6/PAH) nanofibers functionalized with multiwalled carbon nanotubes, used to detect the neurotransmitter dopamine (DA). Miscibility of PA6 and PAH was sufficient to form a single phase material, as indicated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), leading to nanofibers with no beads onto which the nanotubes could adsorb strongly. Differential pulse voltammetry was employed with indium tin oxide (ITO) electrodes coated with the functionalized nanofibers for the selective electrochemical detection of dopamine (DA), with no interference from uric acid (UA) and ascorbic acid (AA) that are normally present in biological fluids. The response was linear for a DA concentration range from 1 to 70 μmol L(-1), with detection limit of 0.15 μmol L(-1) (S/N = 3). The concepts behind the novel architecture to modify electrodes can be potentially harnessed in other electrochemical sensors and biosensors.

Selective electrochemical detection of dopamine in a microfluidic channel on carbon nanoparticulate electrodes.

There is a continuous need for the construction of detection systems in microfluidic devices. In particular, electrochemical detection allows the separation of signals from the analyte and interfering substances in the potential domain. Here, a simple microfluidic device for the sensitive and selective determination of dopamine in the presence of interfering substances was constructed and tested. It employs a carbon nanoparticulate electrode allowing the separation of voltammetric signals of dopamine and common interfering substances (ascorbic acid and acetaminophen) both in quiescent conditions and in flow due to the electrocatalytic effect. These voltammograms were also successfully simulated. The limit of detection of dopamine detected by square wave voltammetry in 1mM solutions of interfering substances in phosphate buffered saline is about 100 nM. In human serum a clear voltammetric signal could be seen for a 200 nM solution, sufficient to detect dopamine in the cerebral fluid. Flow injection analysis allows a decrease in the limit of detection down to 3.5 nM.

Electrochemical detection of dopamine using a bare indium–tin oxide electrode and scan rate control

We report sensitive and selective electrochemical detection of dopamine (DA), a neurotransmitter that plays an important role in organisms. The detection of DA is often prevented by the presence of interfering molecules. Therefore, developing a selective and sensitive technology for detection of DA is necessary. The proposed method simply achieves selective and sensitive detection of DA by scan rate control on bare indium–tin oxide (ITO) electrodes. In the case of a low scan rate (50mVs−1), the anodic peaks of DA and ascorbic acid (AA) appeared at similar potentials (ca. 0.1V) and both of them showed high anodic peaks. On the other hand, with a high scan rate (5Vs−1), the anodic peak of AA almost disappeared, but the DA peak was still high because of the adsorption of DA to the electrode. The detection limit of this method is 1nM of DA in the presence of 0.1mM of AA and 100nM of DA in human blood serum.

Sensitive and selective electrochemical detection of dopamine using an electrode modified with carboxylated carbonaceous spheres

A highly sensitive and selective electrochemical sensor of dopamine (DA) has been developed by employing carboxylated carbonaceous spheres to modify glassy carbon electrodes (GCEs). Scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy were used to characterize as-prepared carbonaceous spheres. The results show that the diameter of carboxylated carbonaceous spheres is uniformly 500 nm and that their surfaces mainly expose carboxyl groups with negative charges. Electrochemical measurements demonstrate that carboxylated carbonaceous spheres greatly improve the accumulation of positively charged dopamine, leading to good sensing performance on a modified GCE. Through applying the differential pulse voltammetric approach, linear calibration curves were obtained in a range of about 0.1 to 40 μM with a detection limit down to 30 nM. Furthermore, depending on the charge-based discrimination, the modified electrode displays good selective detection of DA and reliable anti-interference to UA and glucose besides a weak and negligible response to AA. Therefore, the carboxylated carbonaceous sphere introduced here is a good candidate to develop electrochemical sensors for the sensitive and selective detection of DA.

A Selective Voltammetric Method for Detecting Dopamine at Quercetin Modified Electrode Incorporating Graphene

AbstractThe development of a quercetin‐graphene composite‐modified glassy carbon electrode (Qu/GH/GCE) for the selective and sensitive detection of dopamine (DA) is described in this paper. To fabricate the Qu/GH/GCE, graphene (GH) was first coated onto the surface of a glassy carbon electrode (GCE) and then quercetin (Qu) was electrodeposited on the GH matrix. Transmission electron microscopy (TEM) was used to characterize the morphology of the obtained GH and Qu/GH, and the electrochemical properties of the modified electrode were studied using electrochemical techniques. The as‐prepared Qu/GH/GCE occupied a synthetic property between GH and Qu. The common overlapped electrochemical oxidation peaks of DA and AA were completely separated and a remarkable increasing electron‐oxidation current of DA occurred on the Qu/GH/GCE, which enabled the sensitive and selective electrochemical detection of DA in the presence of ascorbic acid (AA) with peak difference of ca. 452 mV between DA and AA. The peak current obtained at 0.174 V (vs. saturated calomel electrode, SCE) from differential pulse voltammetry (DPV) is linearly dependent on the DA concentration in the range from 3.0×10−8 to 4.0×10−4 mol/L with a detection limit of 1.0×10−8 mol/L. Furthermore, the Qu/GH/GCE exhibits good reproducibility and stability, and has been used for the determination of DA in samples of rat’s striatum tissue with satisfactory results.

A Study on Tannic Acid-doped Polypyrrole Films on Gold Electrodes for Selective Electrochemical Detection of Dopamine

Tannic acid-doped polypyrrole (PPY/TA) films have been grown on goldelectrodes for selective electrochemical detection of dopamine (DA). Electrochemicalquartz crystal microbalance (EQCM) studies revealed that, in vivid contrast toperchlorate-doped polypyrrole films (PPY/ClO4-), the redox switching of PPY/TA filmsin aqueous solutions involved only cation transport if the solution pH was greater than3~4. The PPY/TA Au electrodes also exhibited attractive permselectivity forelectroactive cations, namely, effectively blocking the electrochemical reactions ofanionic ferricyanide and ascorbic acid (AA) while well retaining the electrochemicalactivities of hexaammineruthenium (III) and dopamine as cationic species. A 500 HzPPY/TA film could effectively block the redox current of up to 5.0 mM AA. Thecoexistence of ascorbic acid in the measurement solution notably enhanced the currentsignal for dopamine oxidation, due probably to the chemical regeneration of dopaminethrough an ascorbic acid-catalyzed reduction of the electro-oxidation product ofdopamine (EC’ mechanism), and the greatest amplification was found at an ascorbic acidconcentration of 1.0 mM. The differential pulse voltammetry peak current for DAoxidation was linear with DA concentration in the range of 0 to 10 μM, with sensitivityof 0.125 and 0.268 μA/μM, as well as lower detection limit of 2.0 and 0.3 μM in a PBSsolution without AA and with 1.0 mM coexisting AA, respectively.

Modified Random Assembly of Microelectrodes for the Selective Electrochemical Detection of Dopamine

Modified Random Assembly of Microelectrodes for the Selective Electrochemical Detection of Dopamine

Modified Random Assembly of Microelectrodes for the Selective Electrochemical Detection of Dopamine

A microelectrode assembly of carbon microdisks (RAM electrode) has been used for the electrochemical detection of dopamine in the presence of high concentrations of homovanillic, dihydroxyphenylacetic and ascorbic acids. It is demonstrated that the electroanalytical detection limit (50 nM dopamine) is enhanced compared to results obtained at conventional macrosized carbon electrodes. The surface of carbon microdisks assemblies has been successfully coated by cation exchangers such as Nafion and laponite. Laponite coatings proved to have a higher sensitivity than Nafion films for dopamine detection. Overlapping of anionic interferents is overcome by depositing mixed coatings of Nafion and laponite. Using chronamperometry, due to the attractive combinations of permselective ion-exchange and antifouling properties of (Nafion+laponite)-films at the RAM electrodes, it is demonstrated that discrimination between dopamine and high concentrations of ascorbic acid is achieved.

Selective Electrochemical Detection of Dopamine in the Presence of Ascorbic Acid at Anodized Diamond Thin Film Electrodes

Selective Electrochemical Detection of Dopamine in the Presence of Ascorbic Acid at Anodized Diamond Thin Film Electrodes

Highly selective electrochemical detection of dopamine using interdigitated array electrodes modified with nafion/polyester lonomer layered film

AbstractThe highly selective electrochemical detection of dopamine has been developed using an interdigitated microarray (IDA) electrode coated with Nafion and polyester ionomer (Kodak AQ29D) layered films. Because high redox cycling of dopamine can be maintained in the AQ29D bottom layer, a low detection limit of 50 nmol/dm3 is obtained. Since the upper Nafion laybr prevents L‐ascorbic acid from diffusing into the AQ29D layer, the acid concentration in this layer rapidly decreases when potentiostating one IDA electrode (anode) above and the other (cathode) below the redox potential of dopamine. This is because L‐ascorbic acid molecules in the AQ29D layer are removed quickly by the electrochemical or electrocatalytic oxidation at the anode. On the other hand, almost all of the oxidized dopamine molecules are reduced at the cathode, which maintains a constant dopamine concentration in the film during measurement. After the potential step, the influence of L‐ascorbic acid is almost completely eliminated within a few seconds due to the reduction in acid concentration in the modified layer. As a result, dopamine can be detected quantitatively at the cathode in the presence of 100‐fold excess of L‐ascorbic acid.