Determination Of Dopamine In Presence Research Articles

A Novel Electrochemical Sensor Based on Multi Walled Carbon Nano Tubes/Poly (Evans Blue) Composite for the Determination of Dopamine in Presence of 5-HT and FA

A new sensor was fabricated by electrochemical polymerization of Evans blue (EB) followed by deposition of multi walled carbon nano tubes (MWCNTs) on glassy carbon electrode (GCE). The developed electrode was characterized by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The fabricated electrode was employed for analyzing neurotransmitter Dopamine (DA) drug and its simultaneous determination in presence of serotonin (5-HT) and folic acid (FA) with the help of differential pulse voltammetry (DPV) technique. The effect of pH of phosphate buffer solution (PBS) was studied and pH - 5.0 was found to be an optimum pH value. In the present investigation the kinetic parameters, such as charge transfer coefficient, number of electrons and rate constant values were evaluated. The voltammetric peak currents showed a linear response for DA concentrations from 0.5 to 100 µM and from the linear relationship the limit of detection (LOD) and limit of quantification (LOQ), values were as evaluated as 0.54 µM and 1.8 µM respectively. The fabricated electrode showed good stability, reproducibility and sensitivity. The practical application of the developed sensor in determining DA levels in pharmaceutical formulation was successfully monitored.

Designing hybrid nanocubes-like cobalt stannate with appliance of MWCNT's nano composite for electrochemical detection of dopamine in bio-clinical samples

In this work, Co2SnO4 having nanocubes like structure synthesized via simple co-precipitation method and the nano-composite was prepared with appliance of multi-walled carbon nanotubes (MWCNT's) and employed for the determination of neuro-transmittance of dopamine (DA) in biological sample. The Co2SnO4 nanocubes and Co2SnO4@MWCNTs are characterized through distinct spectroscopic and microscopic methods, such as Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction spectroscopy (XRD), Raman spectroscopy, Filed emission scanning electron microscopy (FE-SEM), and electron spectroscopy for chemical analysis (ESCA) and as well as electrocatalytic activity was examined by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometry techniques. Under optimal circumstances, the nano composite exhibited better activity over bare GCE. Moreover, Glassy carbon electrode (GCE) modified with Co2SnO4@MWCNTs was high sensitive and selective towards the determination of DA in presence of common interfering biomolecules. The electro analytical parameters via wide linear range (50–350 nM), low detection limit of 10.3 nM, sensitivity 0.043 nM mAcm−2 obtained by DPV analysis. The reliability of the Co2SnO4@MWCNTs/GCE electrode confirmed by real sample analysis of human urine sample and dopamine hydrochloride injection shows favor recovery percentage.

Ultrasensitive electrochemical detection of dopamine from human serum samples by Nb2CTx-MoS2 hetero structures

A heterostructure of MXene and MoS2 (Nb2CTx@MoS2) was synthesized and used for the ultrasensitive and selective detection of dopamine (DA). The composite was synthesized using a facile hydrothermal strategy and it was used to modify the carbon cloth (CC). The best composition of the material for DA detection was optimized by varying the content of MoS2 from 6.25 to 25 % while keeping the amount of Nb2CTx constant. From the electrochemical analysis, it was found that Nb2CTx@12.5MoS2 showed the best sensing characteristics owing to the optimum interaction between MoS2 and Nb2CTx. The Nb2CTx@MoS2 modified CC was able to detect DA linearly from 1 fM to 100 µM with a limit of detection (LOD) of 0.23 fM. The LOD of 0.23 fM is the lowest for DA detection in comparison with other MXene-based composites to the best of our knowledge. The developed sensor exhibited promising selectivity for determination of DA in presence of other interferents like uric acid and ascorbic acid. In addition, the developed sensor showed good repeatability, cyclic and storage stability, which shows the potential of this composite for developing flexible electrochemical sensors for the ultrasensitive and selective determination of DA.

Effect of graphite oxide and exfoliated graphite oxide as a modifier for the voltametric determination of dopamine in presence of uric acid and folic acid

In the present work, exfoliated graphite oxide (E-GO) was prepared by sonicating graphite oxide (GO) (prepared by modified Hummer’s and Offemam methods). Prepared GO and E-GO were characterized using infrared absorption spectroscopy, X-ray diffraction, and scanning electron microscopy. The electrocatalytic properties of GO and E-GO towards detection of dopamine (DA), uric acid (UA), and folic acid (FA) were investigated using cyclic voltammetry and differential pulse voltammetry. Our results revealed that E-GO has a slighter advantage over the GO as an electrode modifier for detection DA, UA, and FA, which might be ascribed to the good conductivity of E-GO when compared to the GO.

Amplified oxadiazole derivative nano MgO–multiwall carbon nanotubes modified carbon paste electrode for the determination of dopamine in presence of morphine

AbstractIn this paper, we report the fabrication of an amplified sensor to determine dopamine in the presence of morphine based on nano‐MgO, multiwall carbon nanotubes, and an oxadiazole derivative. The electrochemical behavior and electrocatalyic activity of the sensor toward the oxidation of dopamine were investigated. Cyclic voltammetry was used to study the redox features of the sensor, and the results have shown that dopamine overpotential oxidation at the surface of the sensor was reduced to nearly 460 mV. The diffusion coefficient was estimated by chronoamperometry. Three segmented linear dynamic ranges over the range 0.05–5175.0 and detection limit of 0.021 μM for the quantification of dopamine were obtained using differential pulse voltammetry (DPV). The modified nanocomposite carbon paste electrode, which showed excellent sensitivity, selectivity, repeatability, and reproducibility, was satisfactorily employed to determine dopamine and morphine in actual samples.

Selective Determination of Dopamine in Presence of Ascorbic Acid Using Nafion Coated Methylene Blue Functionalized Graphite Electrode

An electrochemical sensor has been developed using methylene blue (MB) unctionalized graphite for the selective determination of dopamine in the presence of ascorbic acid. The immobilization of methylene blue on graphite was done by carbodiimide coupling method. The methylene blue functionalized graphite was characterized by SEM, FTIR spectroscopy and UV-visible spectroscopy. The immobilization of methylene blue functionalized graphite (MB-G) on the electrode surface was made by drop casting a small volume of MB-G dispersed methanol solution on the electrode surface. About 5 L of 0.5 % Nafion solution was also dropcasted for the stability and selectivity. The MB-G modified electrode was characterized by cyclic voltammetry. The modified electrode promotes the electrocatalytic oxidation of dopamine at a lower potential of 160 mV. The selective determination of dopamine in the presence of 100 times higher concentration of ascorbic acid was achieved by differential pulse voltammetry. The modified electrode offered a simple, selective and sensitive determination of low levels of dopamine. Also the oxidation over potential was reduced to an extent of 360 mV comparing with the bare graphite electrode. The proposed sensor has the advantage of easy fabrication, low cost, good sensitivity, reproducibility and stability.

A Facile Hydrothermal Synthesis of Three Dimensional Flower-Like NiO-Thermally Reduced Graphene Oxide (trGO) Nanocomposite for Selective Determination of Dopamine in Presence of Uric Acid and Ascorbic Acid.

Three dimensional flower-like NiO-thermally reduced Graphene Oxide (trGO) nanocomposite was prepared by a simple hydrothermal method. The morphology and structure of the nanocomposite was characterized using Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Energy Dispersive X-ray (EDX), X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy. The electrocatalytic oxidation of Dopamine, Ascorbic Acid (AA) and Uric Acid (UA) was investigated using Cyclic Voltammetry (CV). The modified electrode NiO-trGO/GCE showed good electrocatalytic activity compared to bare GCE. The detection of dopamine was carried out using Differential Pulse Voltammetry (DPV) wherefrom the Limit of Detection (LOD) and linear range was estimated to be 50 nM and 10 μM to 500 μM respectively. The selective detection of dopamine in presence of UA and AA was carried out. The NiO-trGO/GCE showed excellent selectivity for the detection of dopamine in presence of UA. However AA was found to interfere in the determination of dopamine. Also, the validity of the present sensor was examined in human biological samples.

Trouble Free Dopamine Sensing by Palladium Nanoparticles Fabricated Poly(3,4-ethylenedioxythiophene) Functionalized Graphene

An electrochemical sensor based on poly(3,4-ethylenedioxythiophene) functionalized reduced graphene oxide with palladium nanoparticles (Pd/PEDOT/rGO) has been constructed for electrochemical determination of dopamine (DA) in presence of ascorbic acid (AA) at high concentration. The structural features of the catalyst were characterized using several instrumental methods. The transmission electron microscopy (TEM) analysis suggests a well dispersed spherical PdNPs set successfully onto PEDOT/rGO film. Electrochemical determination of DA in presence of AA was investigated on modified glassy carbon electrode in 0.1 M phosphate buffer solution at pH 7.4 using cyclic voltammetry, differential pulse voltammetry (DPV) and amperometry techniques. A wider linear analytical range for DA detection (1–200 μM) and comparatively lower limit of detection (LOD) 0.14 μM were obtained using DPV technique, while LOD increases up to 0.16 μM in the presence of five times higher AA. Also, no significant interference was observed from similar biomolecule species such as norepinephrine, epinephrine, uric acid and AA. This DA-sensor retained 85.6% of its initial response up to 15 days.

Nitrogen-Doped Graphene Supported Cobalt Oxide for Sensitive Determination of Dopamine in Presence of High Level Ascorbic Acid

In this report, nitrogen-doped reduced graphene oxide supported cobalt in mixed-oxide (NrGO-Co3O4) has been prepared by simple hydrothermal method and applied as an electrocatalyst for the selective determination of dopamine (DA) over in various biointerfering molecules. Various instrumental analyses have confirmed that the NrGO-Co3O4 nanocomposite has prepared successfully. The detection of DA at as prepared NrGO-Co3O4 has verified through various electrochemical techniques in a 0.1 M phosphate buffer solution (PBS) at pH 7.4. No significant interference has observed in presence of several electroactive interferences; especially, 1000 magnitude higher concentration of AA has shown insignificant interference in the DA detection on NrGO-Co3O4. Overall analytical performance demonstrates a good DA sensing at NrGO-Co3O4 with better sensitivity (369 μA mM−1 cm−2), long detection range (0.3−800.8 μM) and lower detection limit (0.029 μM). The catalytic rate constant and diffusion coefficient for DA detection has been calculated as 6.6 × 104 M−1 s−1 and 5.05 × 10−6 cm2 s−1, respectively. This proposed electrocatalyst has finally shown very satisfactory result on real urine sample analysis.

Determination of dopamine in presence of ascorbic acid and uric acid using poly (Spands Reagent) modified carbon paste electrode.

In this paper, we have fabricated a modified carbon paste electrode (CPE) by electropolymerisation of spands reagent (SR) onto surface of CPE using cyclic voltammetry (CV). The developed electrode was abbreviated as poly(SR)/CPE and the surface morphology of the modified electrode was studied by using scanning electron microscopy (SEM). The developed electrode showed higher electrocatalytic properties towards the detection of dopamine (DA) in 0.1M phosphate buffer solution (PBS) at pH7.0. The effect of pH, scan rate, accumulation time and concentration of dopamine was studied at poly(SR)/CPE. The poly(SR)/CPE was successfully used as a sensor for the selective determination of DA in presence of ascorbic acid (AA) and uric acid (UA) without any interference. The poly(SR)/CPE showed a good detection limit of 0.7 μM over the linear dynamic range of 1.6 μM to 16 μM, which is extremely lower than the reported methods. The prepared poly(SR)/CPE exhibited good stability, high sensitivity, better reproducibility, low detection limit towards the determination of DA. The developed method was also applied for the determination of DA in real samples.

A nanocomposite prepared from helical carbon nanotubes, polyallylamine hydrochloride and CdSe quantum dots for electrochemiluminescent determination of dopamine

A nanocomposite consisting of helical carbon nanotubes, polyallylamine hydrochloride and CdSe quantum dots was synthesized and used for the electrochemiluminescent determination of dopamine in presence of peroxodisulfate. The nanocomposite was characterized by transmission electron microscopy, UV-absorption and photoluminescence spectroscopy. The electrochemical process was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Under optimized conditions, the ECL intensity decreases linearly with the concentration of dopamine in the 1.0 × 10-9 mol · L-1 to 2.0 × 10-5 mol · L-1 range, with a 0.2 × 10-9 mol · L-1 detection limit. The method represents a rapid, simple and sensitive protocol for the determination of dopamine.

The Determination of Dopamine in Presence of Serotonin on Dopamine-Functionalized Electrochemically Prepared Graphene Biosensor

Reported herein is the synthesis of electrochemically prepared graphene with dopamine (DA) functionalization and its application for the electrochemical detection of DA in presence of serotonin (5-HT). Graphene oxide-DA (GO-DA) resulted from the condensation reaction of GO and DA. It was characterized via several instrumental methods. The electrochemical reduction of GO-DA (ERGO-DA) has been employed for the electrochemical detection of DA without and with 5-HT. The electrochemical detection of DA has been verified through cyclic voltammetry, differential pulse voltammetry, and amperometric techniques in a 0.1 M phosphate buffer saline (PBS, pH 7.4). The influence of the accumulation time and pH of the PBS at ERGO-DA modified electrode for DA oxidation has been investigated. The interference has also been performed using interfering substances such as 5-HT, glucose, ascorbic acid, H2O2, and uric acid. The detection limit and linear range of DA have been calculated as 0.04 μM and 0.5–100 μM, respectively, (where s/n = 3) at the ERGO-DA modified electrode. The real sample analysis has done without any difficulty and this biosensor can be used up to 10 days.

Selective determination of dopamine in presence of ascorbic acid and uric acid at hydroxy double salt/surfactant film modified carbon paste electrode

A sensitive and selective electrochemical method using a hydroxy double salt/surfactant film modified carbon paste electrode (HDS/SDS/CPE) was developed for the electrochemical determination of dopamine. The HDS/SDS/CPE shows an excellent electrocatalytic activity towards the oxidation of dopamine in 0.1M phosphate buffer solution (pH 7.4) and the detection limit of DA was 1×10−7M. The interference studies showed that the modified electrode exhibits an excellent selectivity towards dopamine (DA) in the presence of large excess of ascorbic acid (AA) and uric acid (UA). The separation of the oxidation peak potentials for DA–AA and DA–UA were about 187.8mV and 110.7mV respectively. The differences are large enough to determine AA, DA and UA individually and simultaneously. This work provides a simple and easy approach to selectively detect the dopamine in the presence of ascorbic acid and uric acid in physiological samples.

Functionalized-graphene modified graphite electrode for the selective determination of dopamine in presence of uric acid and ascorbic acid

Graphene is chemically synthesized by solvothermal reduction of colloidal dispersions of graphite oxide. Graphite electrode is modified with functionalized-graphene for electrochemical applications. Electrochemical characterization of functionalized-graphene modified graphite electrode (FGGE) is carried out by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The behavior of FGGE towards ascorbic acid (AA), dopamine (DA) and uric acid (UA) has been investigated by CV, differential pulse voltammetry (DPV) and chronoamperommetry (CA). The FGGE showed excellent catalytic activity towards electrochemical oxidation of AA, DA and UA compared to that of the bare graphite electrode. The electrochemical oxidation signals of AA, DA and UA are well separated into three distinct peaks with peak potential separation of 193mv, 172mv and 264 mV between AA–DA, DA–UA and AA–UA respectively in CV studies and the corresponding peak potential separations in DPV mode are 204mv, 141mv and 345mv. The FGGE is successfully used for the simultaneous detection of AA, DA and UA in their ternary mixture and DA in serum and pharmaceutical samples. The excellent electrocatalytic behavior of FGGE may lead to new applications in electrochemical analysis.

Determination of Dopamine in Presence of Uric Acid at Poly (Eriochrome Black t) Film Modified Graphite Pencil Electrode

A simple commercial graphite pencil electrode was used to investigate the electrochemical oxidation of dopamine. The electropolymerised film of eriochrome black t was prepared on the surface of graphite pencil electrode by using cyclic voltammetry technique. The prepared electrode exhibits an excellent electrocatalytical activity towards the determination of dopamine. The effects of concentration, pH and scan rate were investigated. Simultaneous detection of dopamine and uric acid was investigated by using both cyclic voltammetric and differential pulse voltammetry technique. The modified electrode was also used for the detection of dopamine in injection.

Poly(3,4-ethylene-dioxythiophene) electrode for the selective determination of dopamine in presence of sodium dodecyl sulfate

A novel biosensor using poly(3,4-ethylene dioxythiophene) (PEDOT) modified Pt electrode was developed for selective determination of dopamine (DA) in presence of high concentrations of ascorbic acid (AA) and uric acid (UA) with a maximum molar ratio of 1/1000, and 1/100 in the presence of sodium dodecyl sulfate (SDS). SDS forms a monolayer on PEDOT surface with a high density of negatively charged end directed outside the electrode. The electrochemical response of dopamine was improved by SDS due to the enhanced accumulation of protonated dopamine via electrostatic interactions. The common overlapped oxidation peaks of AA, UA and DA can be resolved by using SDS as the DA current signal increases while the corresponding signals for AA and UA are quenched. The use of SDS in the electrochemical determination of dopamine using linear sweep voltammetry at modified electrode PEDOT/Pt resulted in detecting dopamine at relatively lower concentrations. The DA concentration could be measured in the linear range of 0.5 to 25 μmol L − 1 and 30 μmol L − 1 to 0.1 mmol L − 1 with correlation coefficients of 0.998 and 0.993 and detection limits 61 nmol L − 1 and 86 nmol L − 1 , respectively. The validity of using this method in the determination of dopamine in human urine was also demonstrated.

Selective Determination of Dopamine in Presence of Ascorbic Acid at Indium Tin Oxide Electrode

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Electrochemical Sensor for the Determination of Dopamine in Presence of High Concentration of Ascorbic Acid Using a Fullerene‐C60 Coated Gold Electrode

AbstractA fullerene‐C60‐modified gold electrode is employed for the determination of dopamine in the excess of ascorbic acid using square‐wave voltammetry. Based on its strong catalytic function towards the oxidation of dopamine and ascorbic acid, the overlapping voltammetric response of both the biomolecules at the bare electrode is resolved into two well‐defined voltammetric peaks with lowered oxidation potential and enhanced oxidation currents. Linear calibration curves for dopamine are obtained using square‐wave voltammetry over the concentration range 1 nM–5.0 μM in 0.1 M phosphate buffer solution at pH 7.2 with a correlation coefficient of 0.9931 and the detection limit (3σ) is estimated to be 0.26×10−9 M. The interference studies showed that the presence of physiologically common interferents (i.e. uric acid, citric acid, tartaric acid, glucose and sodium chloride) negligibly affects the response of dopamine. The practical analytical utility of the method is illustrated by quantitative determination of dopamine in commercially available pharmaceutical formulation and human body fluids, viz. urine and blood plasma, without any preliminary treatment.