Chemically Enhanced Polymer-Coated Carbon NanotubeElectronic Gas Sensor for Isopropyl Alcohol Detection

摘要

Breathing-air quality within commercial airline cabins has come under increased scrutiny because of the identification of volatile organic compounds (VOCs) from the engine bleed air used to provide oxygen to cabins. Ideally, a sensor would be placed within the bleed air pipe itself, enabling detection before it permeated through and contaminated the entire cabin. Current gas-phase sensors suffer from issues with selectivity, do not have the appropriate form factor, or are too complex for commercial deployment. Here, we chose isopropyl alcohol (IPA), a main component of de-icer spray used in the aerospace community, as a target analyte: IPA exposure has been hypothesized to be a key component of aerotoxic syndrome in pre, during, and postflight. IPAs proposed mechanism of action is that of an anesthetic and central nervous system depressant. In this work, we describe IPA sensor development by showing (1) the integration of a polymer as an IPA capture matrix, (2) the adoption of a redox chemical additives as an IPA oxidizer, and (3) the application of carbon nanotubes as an electronic sensing conduit. We demonstrate the ability to not only detect IPA at 100–10 000ppm in unfiltered, laboratory air but also discriminate among IPA,isoprene, and acetone, especially in comparison to a typical photoionizationdetector. Overall, we show an electronic device that operates at roomtemperature and responds preferentially to IPA, where the increasein the resistance corresponds directly to the concentration of IPA.Ultimately, this study opens up the pathway to selective electronicsensors that can enable real-time monitoring in a variety of environmentsfor the force health prevention and protection, and the potentialthrough future work to enable low parts-per-million and possibly highparts-per-billion selective detection of gas-phase VOCs of interest.