Our breath can say a lot about us--and not just what we had for lunch.
Engineers at the University of Florida are reporting that they have designed a tiny and affordable sensor that can do what has up until now been considered impossible: detect glucose (as well as pH and alkalinity) levels in breath condensate.
Fan Ren, professor of chemical engineering and a researcher for this project, says that the team's most recent research, published in the January issue of IEEE Sensors Journal, upsets long-held assumptions that glucose levels in breath are too small for accurate readings; the sensor, Ren says, uses a semiconductor that amplifies the minute signals to readable levels.
"Instead of poking your finger to get the blood, you can just breathe into it and measure the glucose in the breath condensate," he said.
Coming in at just 100 microns, the tiny sensor is so small that it can get a pH or glucose reading from a single breath in less than five seconds. This is a big improvement over not only finger pricks, but also the current technique for measuring pH or alkalinity in a patient's breath to identify and treat asthma attacks, which involves blowing into a tube for 20 minutes to collect enough condensate for an accurate reading.
The sensors work by joining different reactive substances with the semiconductor gallium nitride, which is commonly used in amplifiers in cell phones, power grid transmission equipment, etc., Ren says. During a reaction, the charge on the semiconductor device changes, and that change provides information on proteins, glucose, pH, etc.
For instance, when targeting cancer they use an antibody sensitive to certain proteins thought to be indicative of cancer. And when targeting glucose levels, the reactive molecules comprise zinc oxide nanorods that bind with glucose enzymes.
Each chip costs as little as 20 cents, and when combined with applications to wirelessly transmit the data, will likely total around $40, Ren estimates--an amount that could be cut in half with mass production.
The researchers have already published more than a dozen peer-reviewed papers on various versions of and uses for this sensor, and have patented or are in the process of patenting several elements of the technology as companies express interest in pursuing the research.