COVID-19 testing with just a single breath

A disposable breathalyser and portable reading device are all that is needed for a new, fast and accurate COVID-19 mass screening test developed by NTU scientists.

Named TracieX, the breathalyser contains a sensor chip designed by NTU researchers that traps and intensifies certain key molecules in the breath.

More than 1,400 individuals have been tested using TracieX at trials at the National Centre for Infectious Diseases and Changi Airport Terminal 1, including at two hospitals in Malaysia.

The device is produced by Silver Factory Technology, an NTU spin-off company co-founded by Assoc Prof Ling Xing Yi, Head of NTU’s Division of Chemistry & Biological Chemistry. The company aims to produce at least 200,000 breathalysers a month starting in June 2021, with plans to eventually ramp production up to two million a month.

Every exhalation contains thousands of breath volatile organic compounds (BVOCs). Different diseases cause different types of organ damage and change an individual’s metabolic pathways in different ways. This results in different breath-based metabolite distribution - a healthy person’s BVOC profile will differ from those of an infected person.

A person blows into the breathalyser for 10 seconds and caps it shut. It is then disinfected to avoid cross-contamination before being inserted into a portable reading device. By analysing the BVOCs captured on the breathalyser’s Surface Enhanced Raman Scattering (SERS) chip, the device can tell whether a person is infected with COVID-19 within 2 minutes.

This test is quick, non-invasive, and has a 95% success rate in detecting positive COVID-19 cases, making it suitable for mass-testing sites such as airports and large-scale events.

The breathalyser can be used to screen not just for COVID-19, but other diseases as well, simply by varying the kinds of BVOCs it picks up.

Image: TracieX, the breathalyser, contains a sensor chip designed by NTU researchers that traps and intensifies certain key molecules in the breath. (Credit: NTU Singapore)