Molecularly Imprinted Poly(thionine)-Based Electrochemical Sensing Platform for Fast and Selective Ultratrace Determination of Patulin

Abstract

An innovative approach based on a surface functional monomer-directing strategy for the construction of a sensitive and selective molecularly imprinted electrochemical sensor for patulin (PAT) recognition is described. A PAT imprinted platinum nanoparticle (PtNP)-coated poly(thionine) film was grown on a pre-formed thionine (TH) tailed surface of PtNP-nitrogen-doped graphene (NGE) by electropolymerization, which provided high capacity and fast kinetics to uptake PAT molecules. TH acted not only as a functional monomer for molecularly imprinted polymer (MIP), but also as a signal indicator. Enhanced sensitivity was obtained by combining the excellent electric conductivity of PtNPs, NGE and TH with multi-signal amplification. The designed sensor displayed excellent performance for PAT detection over the range of 0.002–2 ng mL–1 (R2 = 0.995) with a detection limit of 0.001 ng mL–1 for PAT. In addition, the resulting sensor showed good stability and high repeatability and selectivity. Furthermore, the feasibility of its applications has also been demonstrated in the analysis of real samples, providing novel tactics for the rational design of MIP-based electrochemical sensors to detect a growing number of deleterious substances.