Oxidation Of Methyldopa Research Articles

Green synthesis of perovskite-type TbFeO3/CuO as a highly efficient modifier for electrochemical detection of methyldopa

In this study, TbFeO3/CuO nanocomposite was synthesized with a low-cost, simple and green method in the presence of Crataegus, Ribes and black tea which are acted as fuel or alkalizing agents. The scanning electron microscopy (SEM), and X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and vibrating-sample magnetometer were employed (VSM) for characterizing TbFeO3/CuO nanocomposite. Moreover, an electrochemical sensor based on a carbon paste electrode (CPE) modified by TbFeO3/CuO for quantitative detection of methyldopa (MD) was fabricated. The TbFeO3/CuO nanocomposite exhibited a good electrocatalytic signal towards oxidation of MD. The cyclic voltammetry (CV) confirmed that the MD oxidation at the TbFeO3/CuO/CPE follows an irreversible and diffusion-controlled mechanism. In addition, the MD oxidation peak current achieved by the differential pulse voltammetry (DPV) displayed a linear increase with its concentration at a range between 0.04 and 300 μM and limit of detection (LOD) of 0.009 μM was calculated for MD. Finally, it has been found that the newly developed electrode is very suitable for MD sensing as a result of benefits such as simplified operations, easy procurement, a wider linear range, and proper stability and selectivity. These analytical capabilities support the direct and rapid MD determination in biological and drug samples.

First report for simultaneous determination of methyldopa and hydrochlorothiazide using a nanostructured based electrochemical sensor

An electrochemical method has been described for the voltammetric oxidation and determination of methyldopa (MD) at a carbon paste electrode (CPE) modified with 5-amino-2′-ethyl-biphenyl-2-ol (5AEB) and carbon nanotubes (CNTs). The results indicated that the voltammetric response of MD was improved distinctly at the surface of modified electrode and the oxidation of MD at the surface of modified electrode occurs at a potential of about 220mV less positive than that of an unmodified CPE. The anodic peak was characterized and the process was diffusion-controlled. The current measured by square wave voltammetry (SWV) presented a good linear property as a function of the concentration of MD in the range of 0.1–210.0μM, with a detection limit of 48.0nM for MD. Also, this modified electrode was used for simultaneous determination of MD and hydrochlorothiazide (HCT) for the first time. Finally, the proposed method was successfully applied to MD and HCT determination in pharmaceutical samples and urine as real samples.

Voltammetric behavior of a multi-walled carbon nanotube modified electrode-ferrocene electrocatalyst system as a sensor for determination of methyldopa in the presence of folic acid

The study of electrochemical behavior and determination of methyldopa (MD) is reported for a carbon nanotube (CNT) modified carbon-paste electrode (CPE) and ferrocene (FC) electrocatalyst. The cyclic voltammetric results indicate that the CNT and FC system can remarkably enhance electrocatalytic activity toward the oxidation of MD. This enhancement leads to a considerable improvement of the anodic peak current for MD, and allows the development of a highly sensitive voltammetric sensor for the detection of MD in real samples. Under optimized conditions on the sensor, the proposed method shows a wider dynamic range (0.1–500 μM) in comparison to other reported electrochemical methods, with a detection limit of 0.08 ± 0.002 μM. In addition, the proposed method was able to determine MD in the presence of folic acid (FA).

Electrochemical Amplified Sensor with Mgo Nanoparticle and Ionic Liquid: A Powerful Strategy for Methyldopa Analysis

In this research, an amplified sensor based on paste electrode (PE) modified with MgO nanoparticle (MgO/NPs) and 1-hexyl-3-methylimidazolium hexafluorophosphate (HMH) was designed and used for determination of methyldopa (MD). The CP/MgO/NPs/HMH showed good catalytic activity toward oxidation of MD and improved drug current about 3.58 times. In addition, CP/MgO/NPs/HMH showed a diffusion process and pH dependence behavior for electro-oxidation of MD in aqueous solution. However, differential pulse voltammogram of CP/MgO/NPs/HMH showed a linear dynamic range to sensing of MD in concentration range 1.0 nM – 400 µM with detection limit 0.5 nM. The recovery range 98.25% - 102.5% was obtained for sensing of MD in real samples using CP/MgO/NPs/HMH.