Covalently Grafted on to the Glassy Carbon Electrode in Non-Aqueous Media of Apigenin and Naringenin as Different Flavonoid Derivatives

In this paper, apigenin (AG) and naringenin (NG) have been studied with the cyclic voltammetric technique using the glassy carbon (GC) electrode. The modification was carried out only in non-aqueous media, while the electrochemical characterization was done in both aqueous and non-aqueous media. 0.1 M tetrabutylammonium tetrafluoroborate (TBATFB) in acetonitrile (MeCN) was used in non-aqueous experiments, Britton-Robinson (BR) buffer solution (pH=2) and 0.1 M KCl solution were used in aqueous experiments. Surface modification experiments were performed in the +0.3 V and +2.8 V potential ranges with a scan rate of 0.1 Vs-1 and 10 cycles for two molecules. The presence of AG and NG at the GC electrode surface was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), contact angle measurement (CAM) technique and atomic force microscopy (AFM). We also investigated the electrochemical oxidation of AG and NG in non-aqueous media and propose a grafting mechanism of AG and NG to the GC electrode surface.