2025 AIChE Annual Meeting

(134c) Detecting Mycotoxins in Apple Juice with a Molecularly Imprinted Polymer Based Sensor

Authors

Emily Calhoun, Michigan Technological University
Yixin Liu, Michigan Technological University
Mycotoxins are toxic secondary metabolites that are produced when fungi contaminate agricultural produce, especially when conditions are favorable. The ingestion of the mycotoxin contaminated produce has nephrotoxic, hepatotoxic, immunosuppression, and carcinogenic effects in humans, posing a health concern. Several regulatory agencies around the world have established Maximum Residue Limits (MRLs), providing a demand for sensitive detection methods for these contaminants in various food samples. In this study, a molecularly imprinted polymer (MIP) based electrochemical sensor was developed for citrinin (CIT) detection. A systematic study of the electrochemical properties of CIT was conducted to identify an optimal detection solution that enhances the electroactivity of CIT within the MIP film. The monomer selected, pyrrole, was electropolymerized on a screen-printed electrode using cyclic voltammetry (CV). An optimization of monomer and template ratio, electropolymerization cycles, and pH was performed to achieve the desired selective analyte recognition. A comparison of the MIP and non-imprinted polymer (NIP) was done to validate the proposed sensor’s characteristics. A nanomaterial layer under the MIP layer was used to boost the electroactive signal of CIT oxidizing, providing high sensitivity and a low limit of detection. The sensor can detect 1 nM CIT, beyond the MRL set for apple juice at 100 μg/kg (~40 nM). Selectivity was investigated against other mycotoxins potentially present in apple juice. Reusability, sensitivity, and reproducibility were also investigated. Lastly, the MIP-based CIT electrochemical sensor was integrated with a portable potentiostat to detect CIT in real apple juice samples. It holds great promise to detect CIT in food samples in low-resources settings.