Sensor For Determination Of Norepinephrine Research Articles

Theoretical screening and electrochemical sensor for determination of norepinephrine using a molecularly imprinted poly (3-amiophenylboronic acid)

Norepinephrine (NE) is the primary catecholamine (CA) of interest in the medical field, as it plays a key role in regulating the hormonal and neurological systems. Some NE concentration dysfunction can lead to a number of serious physical conditions. As a result, quick and sensitive NE detection is most critical in medical technology. Thus, in this research, a molecularly imprinted polymer (MIP) was used to create an electrochemical sensor for the selective detection of NE. Prior to this, functional monomers were chosen through molecular modeling utilizing molecular mechanics and quantum mechanics computations. According to these studies, the 3-aminophenylboronic acid (3-APBA) functional monomer produces the most stable complex with NE in molecular modeling calculations. Based on this, by electropolymerizing 3-APBA in the presence of the template molecule NE, an imprinting polymer film is formed on the screen-printed carbon electrode (SPCE) surface. Stepwise fabrication of imprinted polymer films was examined through differential pulse voltammetry (DPV), cyclic voltammetry (CV), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). The performance of the electrochemical NE sensor removal and rebinding levels of the template was studied and optimized. The selectivity for NE was confirmed by using interference studies of small molecules like dopamine, tyrosine, and serotonin. Under optimum levels, the fabricated MIP sensor had a broad linear range over NE concentrations of 0.1 pM–5 pM; sensitivity: 0.004 mA pM−1; limit of detection: 0.03 pM. It is noteworthy that the newly created MIP sensor was effectively validated for NE detection in plasma samples.

MnCr2O4 nanocomposite modified carbon paste electrode based electrochemical sensor for determination of Norepinephrine: A cyclic voltammetry study

A novel MnCr2O4 nanocomposite modified carbon paste electrode (MnCr2O4/MCPE) based sensor were developed and validated by electrochemical detection of norepinephrine (NE). The MnCr2O4 nanocomposite was synthesized by hydrothermal method. The synthesized nanocomposite was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and Infra Red (IR) spectroscopy techniques. To identify the redox properties of the MnCr2O4/MCPE were examined by cyclic voltammetry studies. The investigation of modified electrode has high electroactive surface area, the oxidation and reduction peak occurred at pH7.4 the supporting electrolyte was 0.2 M phosphate buffer solution. MnCr2O4/MCPE as very low detection limit (LOD) is 0.034 µM, high sensitivity, wide linear range (0.0003 mM to 0.0045 mM), applied to the injection sample analysis and the obtained results are satisfactory, good reproducibility exhibits great potential in practical applications.

Synergetic Effects between a Bipyridyl-Functionalized Metal-Organic Framework and Graphene for Sensitive Electrochemical Detection of Norepinephrine

A sensitive and simple electrochemical sensor for determination of norepinephrine (NE) was developed. The electrode (ERG-UiO-67-bpy/GCE) was fabricated by modifying the glassy carbon electrode with a Zr (IV) metal-organic framework (MOF) with 2,2′-bipyridyl-5,5′-dicarboxylate (UiO-67-bpy) and graphene oxide (GO), followed by electrochemical reduction of GO to ERG (electrochemically reduced graphene). The ERG and UiO-67-bpy components of the composite electrode show a synergic electrocatalytic effect, leading to much enhanced voltammetric response to the oxidation of NE. Comparative studies indicate that the hydrogen bonds between the bipyridyl moiety of the MOF and the 2-aminoethanol moiety of NE play an important role in promoting electron transfer on the electrode surface. Differential pulse voltammetry using the composite electrode shows a wide linear-response concentration range with a submicromolar detection limit of 0.026 μM. The sensor shows good reproducibility and stability and also be used for sensitive simultaneous detection of NE and uric acid.

Nanomolar detection limit for determination of norepinephrine in the presence of acetaminophen and tryptophan using carbon nanotube-based electrochemical sensor

A carbon paste electrode modified by carbon nanotubes and a synthesized hydroquinone derivative (abbreviated as DHB) was fabricated. It was used as an electrochemical sensor for simultaneous determination of norepinephrine (NE), acetaminophen (AC), and tryptophan (Trp). Oxidation potential of NE decreased about 220 mV at the modified electrode in comparison with unmodified electrode because of electrocatalysis of oxidation of NE via EC mechanism at the modified electrode. Differential pulse voltammetry was used for obtaining the calibration plot of NE and two linear range of 0.2–20.0 μM and 20.0–1,500.0 μM and an interesting detection limit (3σ) of 40.0 nM were obtained for NE. Also, simultaneous determination of NE, AC, and Trp was described by the proposed sensor and linear range of 20.0–800.0 μM was found for AC and Trp. Finally, the electrochemical sensor was used for the determination of NE, AC, and Trp in mixture.

Nanogold based electrochemical sensor for determination of norepinephrine in biological fluids

A stable layer of gold nano particles (AuNPs) was deposited on the surface of indium tin oxide (ITO) and was used as an electrode for the detection of norepinephrine (NE) by square wave voltammetry (SWV) and cyclic voltammetry (CV). This modified electrode exhibits potent and persistent electron-mediating behavior and a well-defined oxidation peak towards NE was observed. The peak potential of NE was observed at less positive potential with increase in peak current as compared to bare ITO and bare gold electrodes. NE exhibited two quasi-reversible couples at AuNPs modified ITO over the potential range from −0.6 to 0.8 V in phosphate buffer solution (PBS) (pH 7.2). At optimal experimental condition, the catalytic oxidative peak current was responsive with the NE concentrations ranging from 100 nM to 25 μM. The detection limit was found to be 87 nM. Also, the effect of pH revealed that the oxidation of NE at the AuNPs modified ITO involved the transfer of equal number of protons and electrons. The interfering effect of common coexisting metabolites in blood and urine has also been reported. The modified electrode exhibited high stability and reproducibility. A comparison of results with high performance liquid chromatography (HPLC) signalizes a good agreement.

A highly sensitive nanostructure-based electrochemical sensor for electrocatalytic determination of norepinephrine in the presence of acetaminophen and tryptophan

A new electrochemical sensor for the determination of norepinephrine (NE), acetaminophen (AC) and tryptophan (Trp) is described. The sensor is based on carbon paste electrode (CPE) modified with 3,4-dihydroxybenzaldehyde-2,4-dinitrophenylhydrazone (DDP) and takes the advantages of carbon nanotubes (CNTs), which makes the modified electrode highly sensitive for the electrochemical detection of these compounds. Cyclic voltammetry (CV) at various scan rates was used to investigate the redox properties of the modified electrode. The apparent charge transfer rate constant, k s, and transfer coefficient, α, for electron transfer between DDP and CNT paste electrode were calculated. The mediated oxidation of NE at the modified electrode was investigated by CV and the values of k, α and diffusion coefficient ( D) were calculated. Under the optimum pH of 7.0, the oxidation of NE occurs at a potential about 215 mV less positive than that of the unmodified CPE. Differential pulse voltammetry (DPV) of NE at the modified electrode exhibited two linear dynamic ranges with a detection limit (3 σ) of 77 ± 2 nM. DPV was used for simultaneous determination of NE, AC and Trp at the modified electrode, and quantitation of NE in some real samples by the standard addition method.