Investigation of Electrochemical Behaviour of Quercetin on the Modified Electrode Surfaces with Procaine and Aminophenyl in Non‐Aquous Medium

Abstract

In this study, cyclic voltammetry and electrochemical ımpedance spectroscopy have been used to investigate the electrochemical behaviour of quercetin (3,3′,4′,5,7-pentahydroxyflavone) on the procaine and aminophenyl modified electrode. The modification of procaine and aminophenyl binded electrode surface with quercetin was performed in +0,3/+2,8 V (for procaine) and +0,4/+1,5 V (for aminophenyl) potential range using 100 mV s-1scanning rate having 10 cycle. A solution of 0.1 M tetrabutylammonium tetrafluoroborate in acetonitrile was used as a non-aquous solvent. For the modification process a solution of 1 mM quercetin in 0.1 M tetrabutylammonium tetrafluoroborate was used. In order to obtain these two surface, a solution of 1 mM procaine and 1 mM nitrophenyl diazonium salt in 0.1 M tetrabutylammonium tetrafluoroborate was used. By using these solutions bare glassy carbon electrode surface was modified. Nitrophenyl was reduced to amine group in 0.1 M HCl medium on the nitrophenyl modified glassy carbon elelctrode surface. Procaine modified glassy carbon electrode surface was quite electroactive. Although nitrophenyl modified glassy carbon elelctrode surface was electroinactive, it was activated by reducing nitro group into amine group. For the characterization of the modified surface 1 mM ferrocene in 0.1 M tetrabutylammonium tetrafluoroborate for cyclic voltammetry and 1 mM ferricyanide/ferrocyanide (1:1) mixture in 0,1 M KCl for electrochemical impedance spectroscopy were used.

On the electrooxidation mechanism of quercetin glucosides at glassy carbon electrode

“…[36] and that by Mulazimoglu et al in Ref. [37]) that involved application of the electrochemical impedance spectroscopy technique in studies of electrochemical behaviour of quercetin on GC or GC-wax electrode. Nevertheless, discussion of the impedance results presented in the above-mentioned papers was not particularly comprehensive.…”

Electrooxidation of quercetin at glassy carbon electrode studied by a.c. impedance spectroscopy

“…1 below) is a flavonoid of widespread occurrence in plants (caper, lovage, broccoli, lettuce, spinach) and food of plant origin (onions, apples, various berries, tea). Its electrochemical behaviour in different media (including identification and analysis of quercetin's electrooxidation products) [5][6][7][8][9][10][11][12][13][14], as well as application in human nutrition systems [15,16] have successfully been demonstrated. Furthermore, it has been shown in works by Ghica and Brett [17], Brett and Ghica [5], Janeiro and Brett [18], and by Corduneanu et al [19] that the process of electrooxidation of flawonoids, such as: rutin, quercetin, catechin and resveratrol, correspondingly, involves an intermediate adsorption step.…”

Cu (II)-Red Onion Skin Extract-Azo metal Complex - A Potential for Oilfield Applications

“…Onion consists mostly of quercetin content and this is the major flavonoid found in red onion skin [7,8]. More than a million tons of onion skins are thrown off as waste in the European Union [9] and these onion skins are known to contain the highest concentrations of a polyphenolic compound called quercetin and other flavonoids [10,11,12].…”