Elegance is as important in scientific design as it is in art and architecture, chemical engineer Nicholas Kotov believes. Sitting in his austere office at the University of Michigan, in Ann Arbor, he shows off a swatch of black cotton; in heft and feel it's similar to a soft, lightweight dress shirt. But Kotov has transformed the fabric into a biosensor and an electrical conductor simply by dipping it into a solution of carbon nanotubes, antibodies, and a polymer.

Individual, well-formed carbon nanotubes are highly conductive, which makes them promising fo­r applications such as battery electrodes and microprocessors. If molecules such as antibodies are anchored to their surface, they can also serve as very sensitive chemical detectors: when an antibody binds to its target, the nanutobe's electrical properties are measurably altered. But nanotubes tend to clump together, which prevents them from functioning individually. That seriously degrades their electronic properties, says Kotov.