Electroactivated Disposable Pencil Graphite Electrode – New, Cost‐effective, and Sensitive Electrochemical Detection of Bioflavonoid Hesperidin

다국어 초록 (Multilingual Abstract)

In this paper, for the first time, electroactivated disposable pencil graphite electrode (ePGE) was used for the detection of bioflavonoid hesperidin with cyclic and differential pulse voltammetry. The electroactivation efficiency of the pencil graphite electrode (PGE) was examined employing electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) and the enhancement of electron transfer kinetics of the PGE after the electroactivation was found. Hesperidin is irreversibly oxidized on the ePGE and its oxidation was the most pronounced at pH=5.0. Two electrode processes were detected, on one hand, a mixed diffusion and adsorption control was observed for the first electrode process. On the other hand, only diffusion control was observed in the second electrode process. Linear dependence between the peak current and the hesperidin concentration was obtained in the concentration range from 5×10−7 mol dm−3 to 1×10−5 mol dm−3 and the determined lower limit of detection (LOD) was 2×10−7 mol dm−3. Moreover, hesperidin in pharmaceutical formulation (containing active substance, hesperidin, and excipients) was quantified using ePGE. A good correlation was obtained between experimentally obtained hesperidin concentration by voltammetric analysis and concentration determined by standard HPLC technique (R2=0.9462).