Abstract
Polyaniline (PANI) and PANI doped with NiO and/or Al2O3 were tested for their sensing properties towards formaldehyde. It was found that at concentrations above 1 ppm, PANI doped with 5% NiO and 15% Al2O3 had both the sensitivity and selectivity needed, whereas, below 1 ppm, PANI doped with 15% NiO had the sensitivity, but not the selectivity required. By combining both sensing materials into one sensor, a highly sensitive and selective sensor could be made for the detection of formaldehyde at very low concentrations at the toxicity limit of 0.08 ppm.
Acknowledgments
The authors are grateful for financial support from the Natural Sciences and Engineering Research Council (NSERC) of Canada and the Canada Research (CRC) program. Many thanks also to Sober Steering Sensors Canada Inc. and Seacoast Science Inc., USA, for useful discussions.