A highly sensitive and selective electrochemical sensor based on polydopamine functionalized graphene and molecularly...

In this work, a sensitive and selective electrochemical sensor based on polydopamine-reduced graphene oxide (PDA-rGO) and molecular imprinted polymers (MIP) modified glassy carbon electrode for detection of 2,4-DCP was fabricated. The PDA-rGO was obtained through the auto polymerization of dopamine in graphene oxide solution at an alkaline environment. The MIP film was performed on the surface of the PDA-rGO modified electrode by electropolymerization the monomer of o-phenylenediamine (o-PD) with the template of 2,4-dichlorophenol (2,4-DCP). The bare hydroxyl and benzene rings of PDA-rGO could attract positive charged o-PD and provide π-π stacking effect with o-PD and 2,4-dichlorophenol, which made the compact imprinted film and more imprinted sites. The Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to character the MIP and NIP modified electrode in the presence of [Fe(CN)₆]^3-/[Fe(CN)₆]^4- as a probe for signal transduction. The relative current intensity of ferro/ferricyanide decreased linearly with increasing concentration of 2,4-DCP with a detection limit of 0.8 nM (S/N = 3). The MIP sensor had a much higher affinity towards 2,4-DCP than other analogues. The proposed method was successfully applied for the determination of 2,4-DCP in real water samples.