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Voltammetric characterization of hesperidin with electroactivated pencil graphite electrode

Flavonoids represent a large group of polyphenolic compounds which are widely distributed in plants and show beneficial effects on human health. Their biological activity can be connected with structural diversity and a wide range of their derivatives. Hesperidin is a phytochemical classified as bioflavonoid and can be primarily found in citrus fruits as well as in some other fruits and vegetables. Due to suppression of pro- inflammatory cytokine production and its antioxidant defense mechanism, hesperidin shows different pharmacological activities such as cardio protective, antihypertensive, antidiabetic, anti-inflammatory and antihyperlipidemic activity [1]. Graphite can be used as electrode material since it has nonmetallic and metallic properties. The pencil graphite leads are composite materials which contain approximately 65% of graphite, approximately 30 % of clay, and around 5 % is a binder (wax, resins, or high polymer) [2]. The use of disposable pencil graphite electrode (PGE) is proven to be a simple, cheap and fast alternative with superior sensitivity and performance compared to more expensive electrodes [3]. In this study, pencil graphite electrode (PGE) and electroactivated pencil graphite electrode (ePGE) were used for voltammetric characterization of hesperidin in model system with cyclic and differential pulse voltammetry. Both electrodes were characterized with EIS and SECM and the enhancement of electron transfer kinetics was observed after electroactivation. The effect of scan rate, pH and hesperidin concentration on oxidation peak current were also studied. It was determined that oxidation peak current increases with the increase of scan rate and hesperidin concentration. The hesperidin oxidation was the most pronounced at pH = 5. The peak current and the hesperidin concentration showed linear dependence in the concentration range from 5x10-7 mol dm-3 to 1x10-5 mol dm-3. Estimated limit of detection (LOD) was 5x10-7 mol dm-3.

voltammetry ; EIS ; SECM ; hesperidin ; electroactivated pencil graphite electrode

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