A molecularly imprinted electrochemical sensor based on Au nanoparticles-poly(o-phenylenediamine) for diethylstilbestrol detection

Au nanoparticles (AuNPs)-poly(o-phenylenediamine) (PoPD) nanocomposite was facilely prepared by a one-step method and used as the built-in redox probe for the decoration of a glassy carbon electrode (GCE). As the template molecules, diethylstilbestrol (DES) was immobilized on the AuNPs-PoPD/GCE surface by using electropolymerized o -phenylenediamine (oPD) as the imprinting layer, which was then eluted from the imprinting layer with the mixture of ethanol and water (v/v, 50 %). The resultant molecularly imprinted PoPD/AuNPs-PoPD/GCE (MI-PoPD/AuNPs-PoPD/GCE) was used for the electrochemical detection of DES in a wide range from 0.1 to 10 μM, and the limit of detection (LOD) was 0.062 μM (S/N = 3). The parameters for DES detection were also optimized in this work. The molecularly imprinted DES sensor showed high stability, selectivity and reproducibility, and it was successfully used for the detection of DES in the milk samples.