Wireless electroanalysis of mycotoxins with hybrid light-emitting devices based on molecularly imprinted polymers

Abstract

Molecularly imprinted polymers (MIPs) act as “artificial antibodies” offering molecular recognition along with advantages like cost-effective production, versatility, stability, and reusability. These features make MIPs ideal for detecting food contaminants such as mycotoxins, harmful secondary metabolites produced by fungi on cereals, fruits, and vegetables. However, their use as sensors requires a transducer of the analyte binding event. In this work, we report the development of a hybrid light-emitting device for the wireless electroanalysis of zearalenone (ZON), as exemplary mycotoxin with endocrine disrupting activity. Our approach combines the concepts of bipolar electrochemistry (BE) with the fine molecular recognition of a tailored MIP and the optical readout provided by a light-emitting diode (LED). The polymeric-microelectronic hybrid bipolar electrode incorporates a MIP-coated anode and a gold wire cathode to the extremities of a green LED. The MIP responds immediately to the binding of the target mycotoxin, facilitating redox reactions of the electroactive probe ([Fe(CN)6]3⁻/4⁻) at each terminal of the bipolar electrode and triggering the emission of light. A correlation between the intensity of the emitted light and the analyte concentration was obtained. By integrating the BE setup with a microfluidic platform, a highly sensitive analytical device has been built, offering a linear ZON quantification range of 10–70 ng mL⁻¹ , suitable for its quantification in food samples.