Researchers have developed a sensor that can detect disease markers in breath or toxins in air, as well as tell the levels of sickness.

A small and thin square of an organic plastic, the tech could soon be the basis of portable and disposable sensor devices, the team from University of Illinois at Urbana-Champaign said.

In the study published in the journal Advanced Functional Materials, the team lead by Ying Diao demonstrated the device that monitors ammonia in breath, a sign of kidney failure.

"In the clinical setting, physicians use bulky instruments, basically the size of a big table, to detect and analyse these compounds. We want to hand out a cheap sensor chip to patients so they can use it and throw it away," said Diao.

"We developed this method to directly print tiny pores into the device itself so we can expose these highly reactive sites. By doing so, we increased the reactivity by ten times and can sense down to one part per billion," Diao added.

The group is working to make sensors with multiple functions to get a more complete picture of a patient's health.