Trace Ethylene Sensing via Wacker Oxidation

• Main Authors: Fong, Darryl K (Author), Luo, Shao-Xiong (Author), Andre, Rafaela S. (Author), Swager, Timothy M (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Chemistry (Contributor), Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Contributor)
• Format: Article
• Language: English
• Published: American Chemical Society (ACS), 2020-10-27T20:55:59Z.
• Subjects: Article
• Online Access: Get fulltext

Ethylene is a dynamic plant hormone, and its temporal monitoring can be used to glean insight into plant health and status. However, the real-time distributed detection of ethylene at trace levels under ambient conditions remains a challenge. We report a single-walled carbon nanotube-based chemiresistor catalyst combination that can detect ppb levels of ethylene in air. Cycling between Pd(II) and Pd(0) via Wacker oxidation with a nitrite cocatalyst imparts response discrimination driven by the chemoselectivity of the chemical transformation. Sensitivity is controlled by a combination of the chemical reaction efficiency and the n-doping strength of the Pd(0) species generated in situ. The covalent functionalization of the carbon nanotube sidewall with pyridyl ligands drastically improves the device sensitivity via enhanced n-doping. The utility of this ethylene sensor is demonstrated in the monitoring of senescence in red carnations and purple lisianthus flowers.
U.S. Army Engineer Research and Development Center Environmental Quality Technology Program (Contract W912HZ-17-2-0027)
National Science Foundation (Grant DMR-1809740)