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

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 5x10(-7) mol dm(-3) to 1x10(-5) mol dm(-3) and the determined lower limit of detection (LOD) was 2x10(-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 (R-2=0.9462).

Automated summary

In this study, electroactivated disposable pencil graphite electrode was utilized for the detection of bioflavonoid hesperidin, showing a linear relationship between peak current and hesperidin concentration. Two different electrode processes were observed, with the oxidation of hesperidin being irreversible and most pronounced at pH=5.0. Additionally, quantification of hesperidin in pharmaceutical formulations showed a good correlation between voltammetric analysis and standard HPLC technique results.