Rational Construction of Highly Tunable Organic Charge-Transfer Complexes for Chemiresistive Sensor Applications

Organic charge-transfer (CT) complexes with a unique electrical performance are attractive materials for organic electronics. However, achieving breakthroughs in the practical application of CT complexes through rational design have always been a challenge. For the first time, a chemiresistive sensor for nerve agent that mimics (diethyl chlorophosphate) vapor detection is rationally designed based on organic CT complexes. Such CT complex chemiresistive sensor realizes a subppb detection of diethyl chlorophosphate (DCP) within 5 s under atmospheric conditions at room temperature with a high selectivity. Meanwhile, based on the highly tunable characteristics of CT complexes, the influence of morphology and intermolecular interaction on the sensing response are investigated. It is worth noting that a stronger intermolecular interaction results in lower sensing responses for CT complexes with a different D/A combination but with the same ratio. The organic charge-transfer materials not only provide a highly tunable platform for the chemiresistive sensor but also have the special properties such as solution processability, flexibility, and molecular recognition, which provides more possibilities for the application of flexible and wearable biosensors.