Electropolymerized molecularly imprinted polymer film: EIS sensing of bisphenol A

Bisphenol A (BPA) sensing was investigated based on electrochemical impedance spectroscopy (EIS) measurements of an electropolymerized molecularly imprinted polymer (E-MIP) film. The E-MIP film is composed of varying ratios of BPA-terthiophene and carbazole monomer complex deposited onto indium tin oxide (ITO) substrates via anodic electropolymerization using cyclic voltammetry (CV). Subsequently, the interfacial properties of these films were studied using the non-Faradaic EIS technique. The same technique was then used to measure the presence of templated BPA which is a known endocrine disrupting chemical (EDC). Analyses of the EIS results were performed using equivalent circuits in order to model the electrical and impedance properties through the interface. A linear calibration curve was established in the range 0-12 mM concentrations of the analyte. Moreover, the selectivity of the films against bisphenol AF and diphenolic acid was demonstrated. The E-MIP sensor may have advantages in environmental monitoring of bisphenol A in aqueous analyte/pollutant samples.