Electrochemical Determination of Quercetin at β- Cyclodextrin Modified Chemical Sensor: A Voltammetric Study

The electrochemical behaviour of quercetin has been studied at carbon paste electrode (CPE) and β-cyclodextrin modified carbon paste electrode (β-CDMCPE) by employing cyclic voltammetry (CV) and Differential pulse voltammetry (DPV). The β-CDMCPE showed a considerable electrocatalytic effect towards the oxidation peak of quercetin, in Britton- Robinson (BR) buffer pH 2.5, (0.04 M) under, appropriate environment. The anodic peak current is linear to quercetin concentration in the range of 6×10-6 M to 2×10-5 M with detection limited of 3×10-7 M and the limit of quantification of 1.2×10-6 M respectively. The electro catalytic oxidation of quercetin at β-CDMCPE was compared with CPE. The electrochemical process was reversible and adsorption controlled. The interfacial electron transfer phenomenon of quercetin at the modified electrode was deliberated by using electrochemical impedance spectroscopy (EIS), the studies showed that β-CDMCPE was well eminent compared with bare CPE. The electrochemical sensor showed excellent sensitivity towards the determination of quercetin.