Seek-And-Detox For Nerve Agents

A series of small-molecule sensors created by Trevor J. Dale and Julius Rebek Jr. of Scripps Research Institute has the potential not only to detect chemical warfare agents but also to disarm the chemicals in the process (Angew. Chem. Int. Ed., DOI: 10.1002/anie.200902820). Nerve agents such as sarin and tabun are highly reactive organophosphorus compounds that block the enzyme acetylcholinesterase and impair nerve function, often to deadly effect. Several research groups have shown that the oxime functional group (C=NOH) reacts rapidly with organophosphorus nerve agents to defuse them and can even form a basis for antidotes. Building on that work, Dale and Rebek constructed a set of novel water-soluble sensors containing a hydroxy oxime and an aromatic chromophore. In the presence of diisopropylfluorophosphate, a nerve agent mimic, the hydroxy oxime cyclizes to an arylisoxazole, detoxifying the mimic while also producing an enhanced fluorescence signal that can be monitored. Although it isn't known whether the new oximes can detect nerve agents as quickly as existing sensors, they react with diisopropylfluorophosphate more quickly than an oxime-containing nerve agent antidote, the researchers report.