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

Cristina Bertoni,Simone Dal Zilio,Sergio Carrato,Pasquale Naclerio,Emanuele Viviani,Alessandro Fraleoni-Morgera

doi:10.3390/s19061296

Cristina Bertoni, Simone Dal Zilio + Show 4 more

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https://doi.org/10.3390/s19061296

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Abstract

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 at emulating 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 to about 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 either nitrogen or dry air suggest that the mechanisms at work is mainly attributable to specific analyte-semiconducting polymer interactions. These results open the way to the use of P3HT NFs-based sensing elements for the realization of portable, real-time electronic noses for on-the-fly exhaled breath analysis.

Highlights

The sensing elements of gas sensors based on polymers are often constituted by the so-called intrinsically conducting polymers (ICPs), as either doped conjugated polymers presenting an inherent conductivity or conducting polymer composites with carbonaceous materials [1,2]
Previous studies showed that P3HT nanofibers (NF)-based CRs exposed to acetone have very fast response times and nearly perfect baseline recovery [18,19]
We decided to characterize the sensitivity of P3HT NFs-based sensors to gaseous acetone using a flow injection analysis approach, which mimics a dynamic environment [31]

Summary

Introduction

The sensing elements of gas sensors based on polymers are often constituted by the so-called intrinsically conducting polymers (ICPs), as either doped conjugated polymers presenting an inherent conductivity or conducting polymer composites with carbonaceous materials [1,2] These materials are deposited in the form of granular films onto electrodes. When the gaseous analyte adsorbs and penetrates within the grains, it causes a change in the ICP/composite workfunction, which in turn leads to a change in the current detected between the electrodes [3,4,5,6]. Due to this detection mechanism, these devices are termed "chemiresistors".

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