An engineered organic electrochemical transistor (OECT) platform with a highly ammonia-sensitive mesoporous membrane

Abstract

The development of an improved sensor design methodology via an organic electrochemical transistor (OECT)-based organic transistor device is presented here. A polyhydroxyl layer is introduced strategically in the OECT sensor assembly which is composed primarily of poly(3,4-ethylenedioxythiophene) doped with polystyrene-sulfonate (PEDOT:PSS). By introducing this layer, an increased selectivity for ammonia compared to other tested analytes in an aqueous environment has been found. A very low order of magnitude of ammonia concentration was detected by this device at very low operating voltages at room temperature. This superior performance of the OECT device is attributed to the formation of a smart mesoporous bed with electronic properties, which helped to obtain 71.6 ppb as the limit of detection (LOD) for ammonia. This approach incorporates an OECT device platform wherein the sensitivity of the sensor system is enhanced such that improved device performance is achieved while maintaining the cost-effectiveness.