se9b01763_si_001.pdf (922.63 kB)
Proton-Conductive Gas Sensor: a New Way to Realize Highly Selective Ammonia Detection for Analysis of Exhaled Human Breath
journal contribution
posted on 2019-12-12, 22:06 authored by Hongran Zhao, Lichao Liu, Xiuzhu Lin, Jianxun Dai, Sen Liu, Teng Fei, Tong ZhangThe analysis of exhaled human breath has great significance
for
early noninvasive diagnosis. Poor selectivity and strong humidity
are two bottlenecks for the application of gas sensors to exhaled
breath analysis. In this work, we utilized the adsorption, dissolution,
ionization, and migration processes of ammonia in wet nonconjugated
hydrophilic polymers to realize effective ammonia detection. The indispensable
high-humidity atmosphere of exhaled breath was turned into a favorable
condition for ammonia sensing. Nonconjugated polymer sensors can distinguish
ammonia from most other gases because of its extremely high solubility
and good ionization ability. A sensor based on poly(vinyl pyrrolidone)
(PVP) could detect 0.5 ppm ammonia with an extremely high selectivity.
The ammonia-sensing mechanism was thoroughly investigated by complex
impedance plots (CIPs) and a quartz crystal microbalance (QCM) measurement.
Finally, the potential of the PVP sensor for ammonia detection in
exhaled breath was evaluated in simulated environments.