Electrosensing of an alpha-adrenergic agonist psychoactive methyldopa using a sodium bentonite–graphene oxide nanocomposite

Abstract

5In the present report, we describe the preparation of sodium bentonite-graphene oxide nanocomposite for electrosensing of methyldopa (MD). The fabricated electrode materials viz., graphene oxide (GO), sodium bentonite-graphene oxide (Bent-GO) and Bent-electroreduced graphene oxide (Bent-ErGO) were characterized by XRD, FTIR, absorption, Raman, FESEM and AFM methods. Bent-GO suspension was prepared by exfoliation of GO and Bent in water. Bent-GO suspension was drop casted on GCE followed 10 by electrochemical reduction to obtain Bent-ErGO/GCE. Electronic properties of modified GCEs were evaluated employing CV and electrochemical impedance measurements. Redox response of MD increased significantly with the negative shift in peak potentials at Bent-ErGO/GCE compared to that at bare GCE. Based on enhanced electrochemical response, chronoamperometric and differential pulse voltammetric (DPV) methods were developed as alternative analytical methods for the assay of MD. 15 Under optimized conditions, a linear relationship was observed between the peak current and concentration of MD in the range of 1.13 -40.6 µM and 0.1 -60 µM for chronoamperometric and DPV methods, respectively. Furthermore, the proposed electrochemical sensor was successfully employed for the determination of MD in pharmaceutical formulations.

Synthesis and Characterization of Bentonite-Reduced Graphene Oxide Composite: Application as Sensor for a Neurotransmitter, Dopamine

“…37 Nanocomposite Bent graphite oxide suspension was prepared by following the procedure reported earlier. 38,39 Briefly, 0.75 mg graphite oxide and 0.25 mg of Bent was added to 1 ml Millipore water followed by sonication for an hour to get homogeneous suspension of Bent-graphite oxide (Bent-GO) composite.…”

Montmorillonite–graphene oxide hybrids and montmorillonite–graphene oxide/epoxy composite: Synthesis, characterization, and properties

“…Considering the unique structure and high performance of graphene, graphene oxide, and layered silicate, the hybrids of graphene–montmorillonite (GN‐MMT) and graphene oxide–montmorillonite (GO‐MMT) have aroused new interests because the combination may generate synergy effect and hold great potential for polymer composites. Therefore, in recent years, some reports were not only focused on the combination of graphene and silicate clay to prepare GN‐MMT and GO‐MMT hybrids but also involved with the incorporation of these hybrids into some polymer matrix including epoxy , chitosan, rubber , poly(methyl methacrylate‐co‐methacrylic acid)‐polyamide 6 , poly(vinyl alcohol) , and poly(lactic acid) . However, most of these reports mainly studied the synthesis and properties of polymer nanocomposites, while few literatures systematically characterized the hybrids with various GO/MMT ratios and investigated the influence of GO/MMT ratios on the properties of nanocomposites.…”

A Very Simple and Sensitive Spectrofluorimetric Method Based on the Oxidation with Cerium (IV) for the Determination of Four Different Drugs in Their Pharmaceutical Formulations

“…β-blockers also improve the heart's ability to relax and exhibit calming neurological effects decreasing anxiety, nervousness and stabilizing motor performance. 3 Different methods have been employed for the analysis of methyldopa in pharmaceutical formulations including electrochemical methods, [4][5][6][7] spectrophotometry, 1,[8][9][10] kinetic methods, 11 chemiluminescence, 12 capillary electrophoresis (CE) 13 and thin layer chromatography. 14 The main methods of the determination of pioglitazone in pharmaceutical preparations are chromatography, 2,[15][16][17] spectrophotometry, 18,19 electrochemical, 20,21 and thermal methods.…”