Molecularly Imprinted Polymer-Hybrid Electrochemical Sensor for the Detection of β-Estradiol

This paper discusses the construction of a novel electrochemical sensor for 17 beta-estradiol (E2) based on a molecularly imprinted polymer (MIP)-conducting polymer modified hybrid electrode. A bifunctional monomer, N-phenylethylene diamine methacrylamide (NPEDMA), was used for the construction of the electrochemical sensor. Conducting films were prepared on the surface of a gold electrode by electropolymerization of the aniline moiety of NPEDMA. A layer of MIP was photochemically grafted over the polyaniline, via N,N-diethyldithiocarbamic acid benzyl ester (iniferter) activation of the methacrylamide groups. Computational modeling was used to select the most suitable monomer for preparation of MIPs for E2. Experimental parameters such as deposition time, cyclic voltammetric (CV) scan cycles, and conditions for polymer accumulation were optimized. The detection limit of the resulting sensor, determined by CV, was 6.86 x 10(-7) M. Furthermore, the hybrid electrode was successfully used to analyze E2 in water without complex sample pretreatment. These results reveal that the MIP hybrid sensor has potential to be an effective technique for the electrochemical determination of E2 in real-time in complicated matrices.