news of the week gives us the fast time response and the specificity for the nerve agent," Sailor says. 'The point is that using these optical interference fringes is a very sensiA sensor developed by chemists at the tive way of doing detection. University of California, San Diego, se- If you can couple that with lectively detects compounds with a some unique chemistry, phosphorus-fluorine bond like that then you can get a specific found in "G-type" nerve agents such as sensor." sarin, soman, and GF. The new sensor So far, the San Diego reis more selective for G-type nerve searchers have demonagents than competing technologies, strated that they can detect such as surface acoustic wave devices. diisopropylfluorophospho- Second-generation prototype of a chemical sensor for the Chemistry professors Michael J. Sail- nate (DFP), a substance detection of chemical warfare agents fits easily in a hand. or and William C. Trogler, along with that is used to simulate the postdoctoral associates Honglae Sohn structurally related nerve agents sarin, actually more toxic than sarin. However, and Sonia Létant, constructed the sen- soman, and GF. DFP is itself a nerve it is less volatile than sarin. sor from a porous silicon interferometer agent used in neurobiology studies and is Sailor and his coworkers can detect \J. Am. Chem. Soc, 1 2 2 , 5399 DFP at 800 ppm in a stream of air. (2000)]. Sarin's vapor pressure is a factor of 10 higher, Sailor says. "If we can Sailor envisions these siliconCatalytic hydrolysis produces HF see DFP at low concentrations, we based sensors as small and inexthat triggers sensor response should be able to see sarin." pensive devices that can be used by "handfuls or bucketfuls" to The next step is to turn the OH + track nerve agent plumes. 'The sensor into a practical device. / N—Cu- - 0 = P — OR key thing is not only to detect Sailor and electrical and comput \ OR when there's something there but er engineering professor Shaya OPF(OR)2 to be able to track it," he tells Fainman, postdoctoral associate Nerve a g e n t ^ C&EN. 'To track something like a Fang Xu, and undergraduate Mo\ plume, you need to have an array ria Feighery-Ross have built a F OR OH of distributed sensors. You'd like demonstration device and are \ / 1 + to have something that's maybe working with the Defense Ad HO-— P—OR N—Cu—OH? the size of a cell phone that's also vanced Research Projects Agen I 1+ got some radio transmitter eleccy to set up tests with live nerve Catalyst tronics to relay the sensor inforagents. After that, Sailor's role in N —Cumation back to a base station." the device development will be complete. 'We're not a manufac Sailor and Létant earlier P0 2 (OR) 2 turing concern; we're a research showed that HF vapor, one of the OH OH"/ lab," Sailor says. 'We're going to few things that can etch glass, N—Cu—O- P —OR stop at the construction and test can be detected with this surface\ ing of the prototype to see if the oxidized porous silicon interOR -N concept really works." ferometer [Adv. Mater., 12, 355 Note: Ν Ν represents tetramethylethylenediamine Celia Henry (2000)]. HF dissolves the oxide on the surface, changing the optical properties of the interferometer. Deing" campaign embodied by it. A full tection is accomplished by measuring year in development, the new initiatives the blue shift and intensity of interference fringes. The Chemical Manufacturers Associa "are designed to creatively and ef &> ~jr< Sailor and his colleagues incorporate tion is now the American Chemistry fectively articulate the benΦ +Φ a copper hydrolysis catalyst into the ox- Council (ACC). And the new name has a efits of chemistry to ^ * φ Φ ide layer to help detect the nerve new tag line—"Good Chemistry Makes a number of key audiences and &* m ® agents. The catalyst—a tetramethyleth- It Possible." At its 128th annual ylenediamine copper complex that was developed by Trogler's group—hydro- meeting, held last week in lyzes the phosphorus-fluorine bond, re- White Sulphur Springs, leasing HF. The catalyst is mixed with a W.Va., CMA's member surfactant, which accelerates the hy- ship—190 of the largest drolysis. Because the dissolution of the U.S. chemical compa oxide layer is irreversible, the signal is nies—overwhelmingly ap Good Chemistry proved the new name and cumulative. Mokes It Possible 'We incorporated the catalyst, which endorsed the "reposition
Porous Silicon Sensor Detects Chemical Warfare Agents
VI
CMA Gets A Face-lift
American · ^ Chemistry Council
12 JUNE 12, 2000 C&EN
