Trace Ethylene Sensing via Wacker Oxidation
Trace Ethylene Sensing via Wacker Oxidation
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DOI：
10.1021/acscentsci.0c00022
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发表时间：
2020-04-22
影响因子：
18.2
通讯作者：
Swager, Timothy M.
中科院分区：
文献类型：
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作者：
Fong, Darryl;Luo, Shao-Xiong;Swager, Timothy M.
乙烯是一种动态植物激素，其时间监测可用于深入了解植物的健康和状态。然而，在环境条件下实时分布式检测痕量乙烯仍然是一个挑战。我们报告了一种基于单壁碳纳米管的化学电阻催化剂组合，可以检测空气中 ppb 水平的乙烯。通过使用亚硝酸盐助催化剂进行瓦克氧化，Pd(II) 和 Pd(0) 之间的循环可产生由化学转化的化学选择性驱动的响应辨别。灵敏度由化学反应效率和原位生成的 Pd(0) 物质的 n 掺杂强度相结合来控制。碳纳米管侧壁与吡啶基配体的共价功能化通过增强的 n 掺杂极大地提高了器件的灵敏度。这种乙烯传感器的实用性在监测红色康乃馨和紫色桔梗花的衰老过程中得到了证明。
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.