Organic field-effect transistors (OFETs) are electronic devices in which the drain current is controlled by an applied gate voltage. When coupled with appropriate recognition materials, OFETs can serve as sensitive platforms for chemical sensing. Herein, we employed an extended-gate configuration as a chemical sensor design for analyte detection in aqueous media. Among recognition materials, biological materials such as enzymes and antibodies have been widely employed because of their high specificity for their analytes based on the lock-and-key recognition principle. However, the range of detectable analytes is limited by the availability of suitable biological recognition elements. Therefore, synthetic receptors based on molecular recognition chemistry offer a promising approach to designing recognition sites. In this study, molecularly imprinted polymers (MIPs) were applied as recognition materials for selective detection. MIPs provide recognition sites complementary to analytes through polymerization in the presence of template molecules followed by template removal. Quantum chemical calculations can guide their design by evaluating interactions between the template and monomers. These recognition sites contribute to selective detection even in the presence of interferents. In contrast, cross-reactive responses of supramolecular receptors can be combined with pattern recognition methods to discriminate multiple analytes. Furthermore, the integration of microfluidics with the extended-gate-type OFET facilitates real-time monitoring.
This presentation will highlight advances in OFET-based chemical sensing through the integration of organic electronics, molecular recognition chemistry, and microfluidics.