Diagnosing some diseases could be as easy as breathing into a tube.
MIT engineers have developed a test to detect disease-related compounds in a patient’s breath.
The new test could provide a faster way to diagnose pneumonia and other lung conditions.
Rather than sit for a chest X-ray or wait hours for a lab result, a patient may one day take a breath test and get a diagnosis within minutes.
The new breath test is a portable, chip-scale sensor that traps and detects synthetic compounds, or “biomarkers”, of disease, which are initially attached to inhalable nanoparticles.
The biomarkers serve as tiny tags that can only be unlocked and detached from the nanoparticle by a very particular key, such as a disease-related enzyme.
The idea is that a person would first breathe in the nanoparticles, similar to inhaling asthma medicine.
If the person is healthy, the nanoparticles would eventually circulate out of the body intact.
If a disease such as pneumonia is present, however, enzymes produced as a result of the infection would snip off the nanoparticles’ biomarkers.
These untethered biomarkers would be exhaled and measured, confirming the presence of the disease.
Until now, detecting such exhaled biomarkers required laboratory-grade instruments that are not available in most doctor’s offices.
The MIT team has now shown they can detect exhaled biomarkers of pneumonia at extremely low concentrations using the new portable, chip-scale breath test, which they’ve dubbed “PlasmoSniff”.
They plan to incorporate the new sensor into a handheld instrument that could be used in clinical or at-home settings to quickly diagnose pneumonia and other diseases.
“In practice, we envision that a patient would inhale nanoparticles and, within about 10 minutes, exhale a synthetic biomarker that reports on lung status,” says Aditya Garg, a postdoc in MIT’s Department of Mechanical Engineering.
“Our new PlasmoSniff technology would enable detection of these exhaled biomarkers within minutes at the point of care.”
Through these experiments, they showed the sensor quickly detected biomarkers of pneumonia at extremely low, clinically relevant concentrations.
“Our next goal is to have a breath collection system, like a mask you can breathe into,” Garg says.
“A patient would first use something like an asthma inhaler to inhale the nanoparticles. They could then breathe through the mask sensor for five minutes.
“We could then integrate a handheld Raman spectrometer to detect whatever biomarker is breathed out, within minutes.”
Breath tests for disease, sometimes referred to as disease breathalysers, are an emerging technology.
Most designs are still in the experimental stage, and take different approaches to detect various conditions such as certain cancers, intestinal infections, and viruses such as Covid-19.
The MIT team notes that its design can be used to detect diseases beyond pneumonia, as well as biomarkers that are not related to disease, as long as the biomarker of interest has a known vibrational “fingerprint.”
“It’s not just limited to these biomarkers or even diagnostic applications,” Tadesse says.
“It can sniff out industrial chemicals or airborne pollutants as well. If a molecule can form hydrogen bonds with water, we can use its vibrational fingerprint to detect it.
“It’s a pretty universal platform.”