Molecularly Imprinted Poly‐o‐Phenylenediamine Electrochemical Sensor for Entacapone

We have developed a molecularly imprinted polymer (MIP) electrochemical sensor for entacapone (ETC) based on an electropolymerised polyphenylenediamine (Po-PD) on a glassy carbon electrode (GCE) surface. The direct electropolymerisation of the o-phenylenediamine monomer (o-PD) was carried out with ETC as a template. The steps of electropolymerization process, template removal and binding of the analyte were tested by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using [Fe(CN)6]3−/[Fe(CN)6]4 − as a redox probe. The operation of the sensor has been investigated by differential pulse voltammetry (DPV). Under optimal experimental conditions, the response of the DPV was linearly proportional to the ETC concentration between 1.0×10−7 and 5.0×10−6 M ETC with a limit of detection (LOD) of 5.0×10−8 M. The developed sensor had excellent selectivity without detectable cross-reactivity for levodopa and carbidopa. The MIP sensor was successfully used to detect ETC in spiked human serum samples.