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.

中文翻译：

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通过Wacker氧化实现痕量乙烯感测。

乙烯是一种动态的植物激素，其时间监控可用于收集对植物健康和状况的了解。但是，在环境条件下以痕量水平进行乙烯的实时分布式检测仍然是一个挑战。我们报告了一种可检测空气中乙烯的ppb水平的基于单壁碳纳米管的化学反应器催化剂组合。在Pd（II）和Pd（0）之间通过Wacker氧化与亚硝酸盐助催化剂之间的循环赋予了由化学转化的化学选择性驱动的响应区分。通过化学反应效率和原位生成的Pd（0）物种的n掺杂强度的组合来控制灵敏度。碳纳米管侧壁与吡啶基配体的共价官能化通过增强的n掺杂大大提高了器件的灵敏度。