As with the finger prick standard, tests for pH, breast or cancer indicators typically already exist, but they are often cumbersome, expensive or time-consuming, Ren said. For example, the current technique for measuring pH in a patient's breath requires the patient to blow into a tube for 20 minutes to collect enough condensate for a measurement.
At 100 microns, or 100 millionths of a meter, the UF sensor is so small that the moisture from one breath is enough to get a pH or glucose concentration reading in under five seconds, Ren said.
Ren said the sensors work by mating different reactive substances with the semiconductor gallium nitride commonly used in amplifiers in cell phones, power grid transmission equipment and other applications.
If targeting cancer, the substance is an antibody that is sensitive to certain proteins identified as indicative of cancer. If the target is glucose, the reactive molecules are composed of zinc oxide nanorods that bind with glucose enzymes.
Once the reaction happens, "the charge on the semiconductor devices changes, and we can detect that change," Ren said.
While the sensor is not as acutely sensitive as those that rely on nanotechnology, the manufacturing techniques are already widely available, Ren said. The cost is as little as 20 cents per chip, but goes up considerably when combined with applications to transmit the information wirelessly to computers or cell phones. The entire wireless-chip package might cost around $40, he said, although that cost could be cut in half with mass production.
The team has patented or is in the process of patenting several elements of the technology, and several companies have expressed interest in pursuing the research, Ren said.
|Contact: Aaron Hoover|
University of Florida