- A breath test can reveal the health status of a person and indicate the underlying diseases.
- A low-cost, disposable breath sensor has been developed to detect trace compounds in breath.
- The device is made from porous thin films of organic conductive plastics that can detect compounds at levels that are far too low to smell.
A small sensor that can detect disease markers in breath has been developed by a research team at the University of Illinois. The device, made of an organic plastic is sensitive enough to detect compounds at levels that are far too low to smell.
The sensor could soon be the basis of portable and disposable sensor devices. In a study published in the journal Advanced Functional Materials,
professor Ying Diao's research team demonstrated the sensor device that monitors ammonia in the breath, which is a sign of kidney failure.
‘A small sensor has been made from porous thin films of organic conductive plastics to detect disease markers in the breath. This could be the basis for portable, disposable devices for medical and environmental monitoring.’
In a clinical setting, physicians use huge instruments to detect and analyze compounds.
"We want to hand out a cheap sensor chip to patients so they can use it and throw it away," said Diao, a professor of chemical and biomolecular engineering at Illinois.
Previously, many research teams have tried organic semiconductors to detect compounds. But, the materials were not sensitive enough to detect trace levels of disease markers in the breath.
How does the Sensor Detect Ammonia?
Diao's research team found that the reactive sites to detect disease markers were not on the surface of the plastic film, but buried inside it.
"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," said Diao.
The research team focused on detecting traces of ammonia, which is a marker for kidney failure. The team used a material that is highly reactive to ammonia but not other compounds in breath. Monitoring the change in ammonia concentration could indicate kidney health. This could also be an early warning sign for a patient to call their doctor for a kidney function test.
The composition of the sensor can be changed to create devices that can detect other compounds. The team has created an ultrasensitive environmental monitor for formaldehyde, a common indoor pollutant in new or refurbished buildings.
The research team hopes to make sensors with multiple functions to get a complete picture of a patient's health.
"We would like to be able to detect multiple compounds at once, like a chemical fingerprint. 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," said Diao.
- Fengjiao Zhang, Ge Qu, Erfan Mohammadi, Jianguo Mei, Ying Diao. Solution-Processed Nanoporous Organic Semiconductor Thin Films: Toward Health and Environmental Monitoring of Volatile Markers. Advanced Functional Materials, 2017; 1701117 DOI: 10.1002/adfm.201701117