Methane Detection with a Tungsten-Calix[4]arene-Based Conducting Polymer Embedded Sensor Array

The detection of methane is important for industry, environment, and our daily life, but is made challenging by its small size, high volatility, and nonpolar nature. Herein, a tungsten-capped calix[4]arene-based p-doped conducting polymer with hexafluorophosphate or perchlorate counter-anions as a transducer is used to detect methane in dry air. The host-guest interaction between calixarene moieties within the polymer chain and methane molecules leads to the resistance variation of the polymer. The experimental limit of detection (LoD) of methane for the polymer-based sensor is demonstrated to be less than 50 ppm at room temperature, and the extrapolated theoretical LoD of 2 ppm represents exceptional sensitivity to methane. Furthermore, the discrimination of methane from interfering volatile organic compounds is achieved by exploiting a sensor array using complementary chemiresistors and principal component analysis.

Automated summary

A sensor using a special material demonstrates high sensitivity to methane detection in dry air, with a theoretical limit of detection of 2 ppm. Additionally, discrimination of methane from interfering volatile organic compounds is achieved through a sensor array and principal component analysis.