Investigating the electropolymerization process of a geosmin-molecularly imprinted polymer film by CV and EIS

Abstract In this study, a molecularly imprinted membrane (MIP) was prepared on the electrode surface by electropolymerization, in which the template molecule was geosmin (GSM) and the functional monomer was o-phenylenediamine (o-PD). CV results showed that o-PD underwent irreversible oxidative polymerization in the first scan, and the reduction peak current decreased rapidly from 84 μA to 42 μA, due to the insulating film formed on the electrode surface, which effectively hindered electron transport. Electrochemical impedance spectroscopy (EIS) further revealed the changes in the interfacial properties of different modified electrodes. After the elution of template molecules, the charge transfer resistance (Rct) decreased sharply from 3.972 × 10 6 Ω before elution to 7062 Ω, which confirmed the successful modification of the MIP film. Through the synergistic analysis of CV and EIS, this study provided profound insights into the template-monomer interaction, polymerization reaction pathway, and film growth process, thereby establishing an important theoretical and process basis for the controllable electrochemical synthesis of MIP films and their application in the detection of trace odorous substances.