Impedimetric sensor for deoxynivalenol based on electropolymerised molecularly imprinted polymer on the surface of screen-printed gold electrode

Deoxynivalenol (DON), a mycotoxin produced mainly by Fusarium graminearum in contaminated food, is assumed to cause several outbreaks of gastrointestinal disorder among humans. The development of an accurate analytical method for the detection of DON is highly needed to satisfy food safety requirement. In this work, we present an impedimetric sensor based on molecularly imprinted polymer (MIP) of poly o-phenylenediamine (Po-PD) on the surface of screen-printed gold electrode (SPGE), for the determination of DON. The electropolymerisation, template removal and rebinding steps were monitored by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. The Nyquist plots obtained for different steps were analysed and fitted to the modified Randles circuit. At optimal conditions, the charge-transfer resistance (Rct) showed a linear relation with the logarithm of DON concentration in a range from 5.0 to 500.0 ng mL−1, with a limit of detection (LOD) of 0.3 ng mL−1. The sensor exhibited high sensitivity, stability, reproducibility, specificity and acceptable regeneration. The MIP sensor can be reused at least 30 times without loss of affinity towards the template molecule after dry storage in air. It was successfully applied for the determination of DON in food samples.