Electrochemical Detection of Epicatechin in Green Tea Using Quercetin-Imprinted Polymer Graphite Electrode

The current study utilizes molecularly imprinted polymer (MIP) technology to fabricate a cost-effective and reproducible electrode for selective determination and quantitative prediction of epicatechin (EC) in green tea. Acrylamide (AAm) co-polymerized with ethylene glycol dimethacrylate (EGDMA) and optically inactive quercetin (Q) as the template has been used to make the MIP-Q@G material. The voltammetric experiment has been performed using the MIP-Q@G electrode with the help of a three-electrode configuration. In addition to a low detection limit (LoD) of $0.33 ~\mu \text{M}$ , the electrode exhibited two wide ranges of linearity from $1 ~\mu \text{M}$ – $100 ~\mu \text{M}$ and $100 ~\mu \text{M}$ to $500 ~\mu \text{M}$ . The limit of quantitation (LoQ) of the electrode was found to be $1.09 ~\mu \text{M}$ . Partial least square regression (PLSR) and principal component regression (PCR) models have been developed to investigate the predictive ability of the MIP-Q@G electrode using the differential pulse voltammetry (DPV) signals and the high- performance liquid chromatography (HPLC) data. Both PLSR and PCR models achieved prediction accuracies of 94.54 % and 94.41% with a root mean square error of calibration (RMSEC) of 0.113 and 0.119, respectively.