10.dec.06
New York Times Magazine
Malia Wollan
If the mere thought of opening a bag of spinach, using an airplane toilet or touching raw hamburger leaves you petrified, consider the E. coli-detecting wipe developed by Dapeng Li, Margaret Frey and Antje Baeumner at Cornell University.
The story explains that the napkin is made of tiny, superabsorbent nanofibers containing antibodies. When swiped across a surface contaminated with E. coli bacteria (say, the gas-station restroom key), the antibodies activate dyes and turn the wipe red, signaling the presence of microorganisms.
Frey was quoted as saying, "It works similarly to a pregnancy test." Currently, the wipe needs to be dipped into a separate solution containing the dye molecules, but the researchers are at work on a dip-free wipe.
Though not yet ready for the local drugstore, the inexpensive, easily portable and consumer-friendly wipe has successfully identified one E. coli strain, O157:H7, in the laboratory. Frey and her team have their sights set on a wipe that spots a wide spectrum of biohazards, responding with a variety of colored dyes.