An impedimetric determination of zearalenone on MIP-modified carboceramic electrode

Zearalenone (ZEN) is a mycotoxin that poses significant risks to human and animal health due to its mutagenic, immunosuppressive, and carcinogenic properties. This study presents a novel analytical method for detecting ZEN using electrochemical impedance spectroscopy (EIS) combined with a molecularly imprinted polymer (MIP). ZEN, used as the template molecule, was incorporated into polypyrrole on screen-printed electrodes (SPE), and a ZEN-sensitive MIP sensor was created through template removal. The modified sensor surfaces were characterized by EIS and scanning electron microscopy (SEM). An impedimetric MIP sensor for ZEN was developed, offering a detection range from 1 pM to 500 pM. The method's limit of detection (LOD) was established at 1 pM (0.3 pg/mL) with a signal-to-noise ratio of 3 (S/N = 3). The method demonstrated high precision and accuracy, with a maximum relative standard deviation (RSD) of less than 4.4% at a 95% confidence level, and relative error (RE) values ranging from −0.8% to −2.7%. The selectivity of the developed MIP sensor was evaluated using ochratoxin A, ochratoxin B, and aflatoxin B1, with no significant interference observed. ZEN recovery from spiked samples was between 95% and 105%, indicating that the method was successfully applied to grain samples, including corn, rice, and wheat.