Novel breath test to predict kidney failure

Researchers from the University of Illinois (IL, USA) have developed a small sensor that could be utilized for detecting trace concentrations of ammonia in the breath, a potential biomarker for predicting kidney failure.

The study, published in Advanced Functional Materials, outlined how the team developed the highly sensitive sensor by incorporating tunable nanopores into an organic semiconductor film. This allowed for detection of specific chemicals depending on the size of the nanopores that are directly printed into the device, owing to the difference in affinity between pore size and specific volatile organic compounds.

Ying Diao (University of Illinois) commented on the benefits of the sensor: “In the clinical setting, physicians use bulky instruments, basically the size of a big table, to detect and analyze these compounds. We want to hand out a cheap sensor chip to patients so they can use it and throw it away.”

With the capability of detecting different volatile organic molecules, this technology could unlock the potential for monitoring different chemicals for both medical and environmental applications – simply by changing the composition of the sensor.

Although previous studies have demonstrated the use of organic semiconductors for detecting volatile gas compounds before, the sensitivities were not high enough to observe the trace levels that would be required to predict kidney failure. By directly incorporating nanopores into the structure the reactivity between the selected chemical and surface is increased, allowing detection down to 1 part per billion.

The group hopes to use and develop this technology so that it could also detect other molecules which could serve to detect other medical conditions. “We would like to be able to detect multiple compounds at once, like a chemical fingerprint,” Diao stated. “It’s useful because in disease conditions, multiple markers will usually change concentration at once. By mapping out the chemical fingerprints and how they change, we can more accurately point to signs of potential health issues.”

Sources: Zhang F, Qu G, Mohammadi E, Mei J & Diao Y. Solution-processed nanoporous organic semiconductor thin films: toward health and environmental monitoring of volatile markers. Adv Funct Mater. doi:10.1002/adfm.201701117 (2017);
https://phys.org/news/2017-05-sensors-disease-markers.html