Sensors were made from porous thin films of organic conductive plastics. (L. Brian Stauffer)

A small, thin square of an organic plastic that can detect disease markers in breath could soon be the basis of portable, disposable sensor devices. By riddling the thin plastic films with pores, researchers made the devices sensitive enough to detect at levels that are far too low to smell, yet are important to human health.

The research group demonstrated a device that monitors ammonia in breath, a sign of kidney failure. For their first device demonstration, the researchers focused on ammonia as a marker for kidney failure. Monitoring the change in ammonia concentration could give patients an early warning sign to call their doctor for a kidney function test.

The material is highly reactive to ammonia but not to other compounds in breath. But by changing the composition of the sensor, they could create devices that are tuned to other compounds. The group is working to make sensors with multiple functions to get a more complete picture of a patient’s health.