Tiny and disposable sensors that detect organic volatile compounds in breath

Detection of markers for a particular disease can reveal a lot about the health status of an individual. A research team at the University of Illinois has designed tiny sensitive detectors that have the potential to sense volatile organic compounds at a concentration that even our noses cannot sense. Such technology has several applications in the field of medical and other too; however, the team opted to identify ammonia, which is a biomarker for kidney disease, in exhaled breath to validate their sensors.

Ying Diao said, “Usually bulky instruments are used by physicians in the clinical setting to analyze and detect such compounds. We are making efforts to offer patients with a cheap sensor chip that can be used and then discarded.”

The new device, which is made up of permeable slender layers of organic semiconductors, is much alike to the already existing devices used to detect organic substances in exhaled breath. Even though organic semiconductors have been efficient as gas sensors, detecting at low concentration has continued to be a challenge with these sensors. To overcome this, the team ascertained that placing of nanopores between 50 and 70 nm in diameter to the thin film of the organic semiconductor’s surface will result in a significantly greater potential of the substance to react with volatile organic compounds.

For the preliminary illustration of the device, the team considered ammonia, a biomarker for kidney failure. Sensing the alteration in the concentration of ammonia can provide a hint to the patient so as to see a doctor and undertake a kidney function test. The material selected by the team is particularly reactive to ammonia but not to other compounds in the breath. But, by altering the constitution of the sensor, the team can produce sensors that are adjusted for other compounds. For instance, the team has fabricated an ultrasensitive environmental sensor for formaldehyde, an ordinary indoor pollutant in refurbished or new buildings.

At present, the researchers are functioning to develop sensors with several functions in order to receive a complete image of the health of a patient.

We hope the team makes the patients available with cheap and disposable sensors to provide a hint of their health status.