Low cost, portable, fast multiparameter data acquisition system for organic transistor odour sensors

We demonstrate a cost-effective but fast multiparameter data acquisition system for odour sensors based on low threshold organic field effect transistors (OFETs) with an amorphous methoxy-derivative of poly(triaryl amine) (PTA-OMe) as semiconductor. The system applies a simple algorithm to measure OFET saturated transfer characteristics with a tailored operational amplifier circuit that is interfaced to a laptop that controls the circuit and analyses data with bespoke software. Despite the semiconductor's low charge carrier mobility μ ∼ 5 × 10−5 Vs/cm2, the system returns multiparameter OFET data: OFET source–drain current ISD in both the ‘on’ and ‘off’ state, carrier mobility μ, and threshold (VT), in real time (resolution <1 s). The system is tested by exposing the OFET to a series of alcohol odours at different concentrations. Sensor response is quick, and follows a distinct trend IPA > PrOH > EtOH > MeOH.