crease [ligand] interaction, specificity, and sensitivity." Alexander M. Klibanov, professor of chemistry at Massachusetts Institute of Technology, calls the etched beads "a re Using bacterial cells as the masking agent ally interesting idea [that] opens up in in a lithography-like process, British re triguing possibilities." Klibanov believes searchers have etched polymer beads the most exciting potential application is that could function as "smart surfac very sensitive and selective detection of es"—able to target and concentrate anti microorganisms in clinical diagnostic bodies or other affinity ligands and to de tests and in food contamination. "Super tect bacterial contamination. sensitive detection of microbial cells is The key to this multistage process is something that will be of great interest," chemical modification of the polymer he notes. surface with the bacteria acting as tem Vulfson's group begins by partitioning porary protecting groups. In this way, the bacteria—either Listeria monocyto chemically distinct areas matching the genes or Staphylococcus aureus—at the size and shape of the masking bacteria interface between aqueous and organic can be achieved [/. Am. Chem. Soc, 118, solvent phases. The researchers synthe 8771 (1996)]. size polyamide microcapsules, to which "People spend a lot of time perfecting the microorganisms stick. A diacid chlo antibodies, but the problem very often is ride in the solvent mixture forms covanot antibodies, but their supports," says lent bonds with amino groups on the Evgeni N. Vulfson of the Institute of polymer and nucleophilic groups in the Food Research, Reading Laboratory, in bacterial cell wall. The team then cross links a diacrylate in the microcapsule's organic core to pro duce polymer beads with bacteria-stud ded surfaces. With the bacteria in place, the team ties up free amino groups on the polymer sur face by treating the surface with a diisocyanate-derivatized perfluoropolyether. The researchers then re move the bacteria by acid hydrolysis, free ing up amino groups in the sites the bacte ria masked. These amino groups can be used to anchor de sired ligands in the imprinted regions. Micrographs show ethidium bromide-stained Listeria monocytogenes attached to polyamide microcapsules before "We used the perpolymerization of the microcapsule core (upper left), the fluoropolyether be rod-shaped bacteria on the surface of the resultant solid polymer cause we wanted to sphere (upper right), lithographic prints left by the bacteria after their removal from the surface (lower left), and the fluorescence restrict interactions to the functional areas of delineating the imprinted regions after treating the polymer surface with fluorescently labeled Concanavalin A (lower right). the polymer surface," Vulfson says. Random Reading, England. "We're offering anoth binding of bacteria being screened is a sig er way of tackling the problem." An av nificant problem because microorganisms erage solid support might contain 10 an stick to everything, he explains. "The pertibodies per sq μιη, he explains. "Now fluoropolyether fits the bill, because it is you have a way of concentrating antibod very stable and bugs don't recognize it." It ies in hundreds in relatively small patch is important that a "nonsticky" compound es. . . . It's very clear that this will in is used in blocking the functional groups
Bacterial cells etched on polymer surface
on the unetched surface of the beads, he notes. The shape of the imprint is of limited significance for discriminating among mi croorganisms, Vulfson adds, "because you've got a stupid piece of plastic . . . that makes mistakes seven out of 10 times" in recognizing a particular bacterium. But the size is important in sorting cells of differ ent sizes. "There's absolutely no point in concentrating antibodies on a small patch if you've got to bind big cells." Klibanov cautions that "the big un known is how selective those cavities" will be once the technology has been per fected. "You can have some lectin that re acts with all bacteria, and the selectivity will be at the stage of attaching [it] to the beads rather than to the bacteria." How useful the beads will be remains to be seen, he adds. "But I think [finding out] is what science is all about." Mairtn Brennan
Ethyl seeks damages for ban on fuel additive Ethyl Corp. plans to file a $200 million claim against the government of Canada in response to its proposed ban on im port and interprovincial trade of an oc tane-enhancing fuel additive. Methylcyclopentadienyl manganese tricarbonyl (MMT), developed to replace lead in gasoline, has been in use in Canada since 1977. It is manufactured for Ethyl in the U.S. and shipped to and sold by Ethyl Canada, the Canadian subsidiary. Environment Canada (the Canadian environmental protection agency), the U.S. Environmental Protection Agency, automobile manufacturers, and various environmental groups and health organi zations in both countries have long tried to keep MMT out of gasoline. Following a prolonged fight, Ethyl won the right in October 1995 to sell MMT in the U.S., af ter an appeals court ruled that EPA had acted unlawfully in refusing to register it because of health concerns about manga nese emissions (C&EN, Oct. 30, 1995, page 8). Health Canada, the government agency that provides health protection and consumer product safety, has ruled that MMT does not cause health risks as used in gasoline. A bill to ban import and interprovin cial trade of MMT is now in its third read ing in Canada's House of Commons. The bill is based on contentions by automak ers that MMT in gasoline reduces the life SEPTEMBER 16, 1996 C&EN
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n e w s of t h e w e e k of a car's spark plugs and cuts emissions system performance. Indeed, last June, Chrysler, Ford, and General Motors all announced that 1997 car owner's manuals will recommend that gasolines containing MMT not be used if optimum performance is desired. The bill would not ban use of MMT in Canada. But Ethyl stresses that the bill's trade strictures could force closure of Ethyl Canada. "As the sales of MMT represents almost half of Ethyl Canada's total sales revenues, the passage of [the import ban] could effectively force us out of business," says Christopher Hicks, Ethyl's vice president of government relations. "Theoretically, in order to continue operating as a business, Ethyl is being re-
quired to build manufacturing and blending facilities in each of the provinces and territories in Canada," adds David Wilson, president of Ethyl Canada. In response, Ethyl will invoke provisions of the North American Free Trade Agreement that call for an arbitration panel to rule on a government's alleged breach of obligations under NAFTA. Ethyl will seek to recover damages it estimates at $200 million. "As the only manufacturer and distributor of MMT, Ethyl has had its national and international reputation damaged by the [Canadian] government's contention that MMT poses a threat to the environment and human health," Hicks notes. George Peaff
Upgrading of airport bomb detection urged The U.S. should spend $430 million in fiscal 1997 alone to protect passengers from terrorist attacks on airplanes, recommends an Aviation Safety & Security Commission chaired by Vice President Al Gore. In addition to upgrading bomb detection equipment and deploying more bomb sniffing dogs at airports, the commission urges stepped-up funding for airport security research. The panel was set up following the explosion of TWA flight 800, the cause of which is still under investigation. President Clinton asked the panel to study airport security, overall aviation safety, and modernization of air traffic control. The initial report makes 20 recommendations on airport and airline security. Some can be implemented right away; others need congressional approval.
Praising the commission's work, Clinton urges prompt action on several of his legislative initiatives. Among them is addition of taggants to explosives, including black powder, to aid investigators in finding terrorists. "We need all these laws, and we need them now, before Congress recesses for the year," Clinton says. The Gore panel recommends significant spending to upgrade airport detection systems. Noting that no single machine can solve all the challenges airports face, the commission says the federal government should spend more than $161 million this year on computed tomography detection systems, upgraded X-ray equipment, and "other innovative systems." At present, the Federal Aviation Administration (FAA) has approved only one computed tomography system
In test at San Francisco Airport, InVision Technologies' CTX 5000 computed tomography system was installed behind baggage counter to screen for explosives.
8 SEPTEMBER 16, 1996 C&EN
^ for use at airports—the CTX 5000 made by InVision Technologies, Foster City, Calif. (C&EN, July 24, 1995, page 10). This detector is being used at some European airports, but has been tested at only two U.S. airports. El Al Israel Airlines has three of the systems in place in Israel and is now installing one at Kennedy Airport in New York City. The commission stresses that improving airport safety and security will require a government-industry partnership and says this partnership should accelerate R&D to enhance air travel security. The panel recommends that FAA seek an additional $20 million for such research in fiscal 1997, to double what it currently spends. The additional money would fund development of new technologies for explosives detection, aircraft hardening, security technology integration, and aviation security human factors research. Some congressional Republicans aren't too happy about the large amounts the Gore panel wants to spend—coming on top of $550 million already being sought by Clinton for other antiterrorist activities. House Appropriations Committee Chairman Robert Livingston (R-La.) complains that Clinton is promising to spend a lot, but doesn't say where the money will come from. White House Chief of Staff Leon E. Panetta indicates the Administration may try to enact antiterrorism legislation as part of the continuing resolution Congress is expected to approve this month to keep the government running after Sept. 30. David Hanson
C 36 H 12 : A stiff, fullerene-like bowl The generally flat world of polycyclic aromatic hydrocarbons (PAHs) just got a bit curvier. Chemists at Boston College have used flash vacuum pyrolysis (FVP) to synthesize C36H12, a bowl-shaped PAH whose carbon-atom framework comprises 60% of the buckminsterfullerene (C60) soccer ball. Their starting material was the nearly planar PAH decacyclene, a compound that has been known to chemists for 100 years [/. Am. Chem. Soc, 118, 8743 (1996)]. "This molecule is a bridge between the old flat world of organic chemistry and the new round world of fullerenes," says Lawrence T. Scott, the Boston College chemistry professor who carried out
