Nanostructured P3HT as a Promising SensingElement for Real-Time, Dynamic Detection ofGaseous Acetone.

The dynamic response of gas sensors based on poly(3-hexylthiophene) (P3HT) nanofibers(NFs) to gaseous acetone was assessed using a setup based on flow-injection analysis, aimed atemulating actual breath exhalation. The setup was validated by using a commercially available sensor.The P3HT NFs sensors tested in dynamic flow conditions showed satisfactory reproducibility down toabout 3.5 ppm acetone concentration, a linear response over a clinically relevant concentration range(3.5-35 ppm), excellent baseline recovery and reversibility upon repeated exposures to the analyte,short pulse rise and fall times (less than 1 s and about 2 s, respectively) and low power consumption(few nW), with no relevant response to water. Comparable responses' decay times under eithernitrogen or dry air suggest that the mechanisms at work is mainly attributable to specific analytesemiconductingpolymer interactions. These results open the way to the use of P3HT NFs-basedsensing elements for the realization of portable, real-time electronic noses for on-the-fly exhaledbreath analysis.