Electrochemical Detection Of Epinephrine Research Articles

Construction of 2D niobium carbide-embedded silver/silver phosphate as sensitive disposable electrode material for epinephrine detection in biological real samples

Our daily activities are in control and functioned by the neurotransmitter that helps in balancing the signals send to the brain. Epinephrine (EPN) is a commonly known neurotransmitter and the imbalance in EPN leads to several dysfunctions and diseases. Moreover, the uptake of EPN and the importance of EPN have provoked the need for the detection of EPN. Such detection will be helpful in the diagnostics and clinical monitoring of the diseases. The electrode material with intriguing properties for the detection is important and was designed. The niobium carbide (NbC) with silver/silver phosphate (Ag/AgPO) with interesting physical and chemical properties was synthesized. The physical and structural analysis of Ag/AgPO/NbC was characterized by different analytical techniques. The electrochemical detection of EPN was executed after the physicochemical presence of the material. The specific surface area, and high electrical conductivity, with improved active sites enhances the electrochemical performance of EPN. With these properties, the fabricated electrode records a lower limit of detection of about 0.004 μM with a linear range of 0.09–422.45 μM and the sensitivity was about 9.25 μAμM−1cm−2. The other parameter analysis such as repeatability, reproducibility, and stability showed excellent performances at Ag/AgPO/NbC/screen-printed carbon electrode. The real sample analysis with human serum and urine samples also had good recovery results. Thus, the Ag/AgPO/NbC nanocomposite is highly efficient with all these unique features which can be employed in several applications in near future.

Sensitive and selective neurotransmitter epinephrine detection at a carbon quantum dots/copper oxide nanocomposite

Herein, the electrochemical detection of epinephrine (EP) at a carbon quantum dots/copper oxide nanocomposite (CQDs/CuO) modified glassy carbon electrode (GCE) was investigated. The carbon quantum dots (CQDs), copper oxide nanoparticles (CuO NPs), and their composite (CQDs/CuO) were characterized using scanning electron microscopy (SEM), Fourier-Transform infrared spectroscopy (FT-IR), UV–visible spectroscopy, X-ray diffraction (XRD) spectroscopy, Transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). A limit of detection (LoD) of 15.99 µM over a linear dynamic range (LDR) of 10–100 µM was obtained at GCE/CQDs/CuO using the square wave voltammetry (SWV) for EP electroanalysis at pH 7. The theoretical evidence for the conventional weak epinephrinequinone (EPQ) reduction peak and EPQ cyclization was investigated using the density functional theory (DFT) calculations. This sensor was also applied for the analysis of EP in chicken blood serum and EP injection with percentage recovery of 101.23 and 93.54 %, respectively. In addition to its outstanding long-term stability, good reproducibility, and ease of fabrication, the detection of EP in the presence of ascorbic acid (AA) was achieved at this sensor. The proposed sensor also demonstrated the ability to simultaneously detect epinephrine (EP), dopamine (DA), and uric acid (UA).

Electrochemical Detection of Epinephrine at Organic Conducting Polymers Electrodes

In this paper, a rapid and sensitive modified electrode for the determination of Epinephrine (EP) is proposed. In this study, active compound EP was determined from commercial drug form based on electrochemical oxidation properties at various electrodes by voltammetric methods. Electrodes modified by the electrodeposition of conducting organic polymers such as poly(3-methylthiophene, PMT), polypyrrole (PPY) and polyaniline (PAN) were used as chemical sensors for voltammetric analysis and flow injection detection of EP. The electrochemical behavior of EP at conducting polymer electrodes was compared and the effects on behavior of electrolyte type and its pH and the film thickness were systematically examined. The results showed that the proposed modified surface catalyzes the oxidation of EP. Electrocatalytic efficiency decreases in order of PMT > PPY > PAN. Voltammetric peak positions were affected by the nature of the electrolyte and its pH. Also, the effect of increasing film thickness was to observe increased peak heights for oxidation potential of EP. The best results for the determination of EP were obtained by DPV in Na2SO4 (pH 2.0) and PMT electrodes. Polymer coated electrodes were also used in an amperometric detector for flow injection analysis of EP. The responses of the polymer electrode were 5–15 times larger as compared to those of bare platinum. PMT showed improved performance as an amperometric detector for flow injection analysis systems over other types of polymer electrodes. Detection limits as low as 1× 10–9 M were achieved using the PMT, compared to 1 × 10–6 M using platinum electrodes.

Electrochemical detection of Epinephrine using Polyaniline nanocomposite films doped with TiO2 and RuO2 Nanoparticles on Multi-walled Carbon Nanotube

Electrochemical properties of functionalized MWCNT/polyaniline doped with metal oxide (TiO2, RuO2) nanoparticles were explored. Successful synthesis of MWCNT, TiO2, RuO2, PANI, MWCNT-PANI-TiO2, and MWCNT-PANI-RuO2 nano materials were confirmed using suitable characterization techniques. Successful modification of gold (Au) electrode with these nanoparticles was confirmed using electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy. Au-MWCNT-PANI-TiO2 and Au-MWCNT-PANI-RuO2 gave the best electron transport properties towards the oxidation of epinephrine (EP) compared with other electrodes investigated. The Tafel values 0.448 and 0.442V/decade for Au-MWCNT-PANI-TiO2 and Au-MWCNT-PANI-RuO2 electrodes respectively in (EP) suggest adsorption due to analyte oxidation intermediates products. The linear calibration plot was obtained for EP at concentrations range 4.9 to 76.9μM. The limits of detection of EP were estimated to be 0.16 and 0.18μM for Au-MWCNT-PANI-TiO2 and Au-MWCNT-PANI-RuO2 electrodes respectively. The interference study using DPV showed clear peak separation for amino acid (AA) and EP. Therefore, the modified electrodes can selectively detect epinephrine without interference from ascorbic acid signal. The analytical performance of the fabricated sensors has been evaluated for detection of epinephrine (EP) in a pharmaceutical sample with satisfactory results.

Electrochemical detection of epinephrine using a biomimic made up of hemin modified molecularly imprinted microspheres

Electrochemical detection of epinephrine, an important neurotransmitter in mammalian central nervous system, is demonstrated in this study using a simple bio-mimic prepared by hemin modified microspheres of a molecularly imprinted polymer.

Highly selective detection of Epinephrine at oxidized Single-Wall Carbon Nanohorns modified Screen Printed Electrodes (SPEs)

Oxidized Single-Wall Carbon Nanohorns (o-SWCNHs) were used, for the first time, to assemble chemically modified Screen Printed Electrodes (SPEs) selective towards the electrochemical detection of Epinephrine (Ep), in the presence of Serotonine-5-HT (S-5HT), Dopamine (DA), Nor-Epineprhine (Nor-Ep), Ascorbic Acid (AA), Acetaminophen (Ac) and Uric Acid (UA). The Ep neurotransmitter was detected by using Differential Pulse Voltammetry (DPV), in a wide linear range of concentration (2–2500μM) with high sensitivity (55.77AM−1cm−2), very good reproducibility (RSD% ranging from 2 to 10 for different SPEs), short response time for each measurement (only 2s) and low detection of limit (LOD=0.1μM). o-SWCNHs resulted in higher analytical performances when compared with other nanomaterials used in literature for electrochemical sensors assembly.

Functionalized Single‐Walled Carbon Nanotubes Modified Microsensors for the Selective Response of Epinephrine in Presence of Ascorbic Acid

AbstractModified stainless steel microelectrodes (microwire diameter: 300 μm) were assembled using functionalized single‐walled carbon nanotubes (SWCNTs) deposited by the EPD method (electrophoretical deposition process). The functionalized SWCNTs, which covered the microelectrode surfaces, showed an improved sensitivity and selectivity toward the electrochemical detection of epinephrine. These chemical sensors hampered the voltammetric responses of ascorbic acid (AA) and uric acid (UA), while the electrochemical oxidation of epinephrine was significantly enhanced. Using the differential pulse voltammetry (DPV) technique, epinephrine showed a very well resolved peak centered around 240 mV, while 1 mM of AA (present in the same solution) was not detected. The corresponding permeability and permselectivity parameters were also evaluated for ascorbic acid and uric acid. To investigate the sensor selectivity, a comparative study performed using microsensors assembled with non functionalized carbon nanotubes, deposited on the microelectrode surfaces by a chemical vapor deposition (CVD) technique, was also carried out. This study was useful to highlight that the presence, or the absence of electrostatic barriers on SWCNT's walls (due to the presence of some chemical functional groups), can be able to control the electrochemical response of these sensors. This optimization resulted in microsensors with a good linear range (2–100 μM) epinephrine; a good sensitivity (28.1 A M−1 cm−2) and interelectrodes reproducibility (RSD%=7.0, n=6), a detection of limit (LOD=3σ) of 2 μM; a response time of 6 s; a significant operational stability (of 13 hours in continuous working conditions) and long term stability (1 month).