Dual-transduction-mode sensing approach for chemical detection

Smart devices such as electronic nose have been developed for application in many fields like national security, defense, environmental regulation, health care, pipeline monitoring and food analysis. Despite a large array of individual sensors, the resolving power of these devices can still be improved to identify a target at a very low concentration out of a mixture of odors, if different types of transductions are employed in concert as a set of sensing responses to distinguish one odor from another. Here, we propose a new sensor architecture enabling different types of transduction signals in parallel on the same individual sensor. We demonstrate this architecture using a light emitting organic field-effect transistor (LEOFET) operated at a dual-transduction mode, as a proof-of-concept. Sensing response has been observed on both electrical and optical output signals from a green LEOFET upon exposure to an explosive taggant, with optical signal exhibiting much higher sensitivity. This new sensor architecture opens a field of devices of synergic capabilities to distinguish chemical and biological targets.