Electrochemical Determination of Morin in Natural Food Using a Chitosan–Graphene Glassy Carbon Modified Electrode

Abstract

This report presents a new application for the chitosan–graphene glassy carbon electrode (Ch-G/GCE) system in the determination of the hydroxyflavonoid morin (MR), one of the flavonoids with the highest favorable activity for people, due to its natural properties by square-wave voltammetry (SWV). The anodic peak current for MR was observed at 0.50 V with an increase of 73% compared with the glassy carbon electrode unmodified. The surface areas of Ch-G/GCE, Ch/GCE and GCE evaluated by cyclic voltammetry were 0.140, 0.053 and 0.011 cm2, respectively. Additionally, an increase greater than 100% compared to the electrode without modification was observed. The detection limit was 0.30 µmol/L for MR, and the relative standard deviations (RSDs) were 1.8% (n = 6). Possible interferences as quercetin, rutin, and applications in real samples were also evaluated with very acceptable results.

A Simple Electroanalytical Method for Detecting Carminic Acid in Foods through a Glassy Carbon Electrode Modified with Chitosan in the Presence of Allura Red

“…The electroactive properties of the Cs/CGE modified (Figure 1), such as topographic characteristics [16] and active area surface, [17] have been previously reported, in which an 80 % increase in the surface area was observed compared to that of the unmodified electrode. This change in surface area is among the possible causes of the increased activity of Cs-modified glassy carbon electrodes.…”

“…This change in surface area is among the possible causes of the increased activity of Cs-modified glassy carbon electrodes. [17] Similar carbon electrodes modified with Cs have been previously used to detect sunset yellow [15] and rutin combined with ionic liquids, [18] and rutin combined with graphene. [18] In this new report, the surface of the active area was calculated with much lower concentrations of Fe 2 + /Fe 3 + (CN) 6 compared to the concentration normally reported between 5.0 and 10.0 mmol/ L. The results are shown in Figure 2.…”