Electrosynthesis of Nanostructured, Imprinted Poly(hydroxymethyl 3,4‐ethylenedioxythiophene) for the Ultrasensitive Electrochemical Detection of Urinary Progesterone

Abstract

AbstractElectrochemically synthesized polymers are used in molecular imprinting for chemical sensing and are attractive for use in the rapid preparation of low‐cost sensing electrodes. The electropolymerization of certain novel monomers, such as 3,4‐ethylenedioxythiophene (EDOT), results in electrically conducting polymers (ECPs) that give substantially improved biosensor performance. In this work, EDOT and hydroxymethyl EDOT (EDOT‐OH) were electrochemically copolymerized to optimize the imprinting effectiveness of progesterone; the imprinting effectiveness is defined as the ratio of the peak electrochemical response of molecularly imprinted polymers (MIPs) to that of non‐imprinted polymers (NIPs). Interestingly, three different kinds of microstructures were observed: porous, “belt”, and tubular structures. Copolymerization, however, did not increase the effectiveness of imprinting over that obtained with pure PEDOT or p(EDOT‐OH). Finally, urine samples and the interferences that are present in urine (such as creatinine, urea, testosterone and 17β‐estradiol) were examined to determine the selectivity of these sensors. The limit of detection (LOD) of this progesterone sensor was less than 1.0 fg/mL, and the linear range was from 0.1 fg/mL to 0.1 ng/mL.