In a new breathalyzer invented by researchers at Stony Brook University, nanowires enable the sensor to detect just a few molecules of a disease marker gas in a ‘sea’ of billions of molecules of other compounds.

This
invention could give new meaning to the term “bad breath!” It’s the
Single Breath Disease Diagnostics Breathalyzer, and when you blow into
it, you get tested for a biomarker—a sign of disease. As amazing as that
sounds, the process is actually very simple thanks to ceramics
nanotechnology. All it takes is a single exhale.

You
blow into a small valve attached to a box that is about half the size
of your typical shoebox and weighs less than one pound. Once you blow
into it, the lights on top of the box will give you an instant readout. A
green light means you pass (and your bad breath is not indicative of an
underlying disease; perhaps it’s just a result of the raw onions you
ingested recently); however, a red light means you might need to take a
trip to the doctor’s office to check if something more serious is an
issue.

With
support from the National Science Foundation (NSF), Professor Perena
Gouma and her team at Stony Brook University in New York developed a
sensor chip that you might say is the “brain” of the breathalyzer. It’s
coated with tiny nanowires that look like microscopic spaghetti and are
able to detect minute amounts of chemical compounds in the breath.
“These nanowires enable the sensor to detect just a few molecules of the
disease marker gas in a ‘sea’ of billions of molecules of other
compounds that the breath consists of,” Gouma explains. This is what
nanotechnology is all about.

You
can’t buy this in the stores just yet—individual tests such as an
acetone-detecting breathalyzer for monitoring diabetes and an
ammonia-detecting breathalyzer to determine when to end a home-based
hemodialysis treatment—are still being evaluated clinically. However,
researchers envision developing the technology such that a number of
these tests can be performed with a single device. Within a couple of
years, you might be able to self-detect a whole range of diseases and
disorders, including lung cancer, by just exhaling into a handheld
breathalyzer.

Handheld
breath tests to estimate blood alcohol content and nitric oxide
detectors used in hospitals to monitor pulmonary infections have been
around for a while, but there is no consumer-based technology like this
currently available. The research team envisions the cost of the final
product being under $20, just one of many reasons Gouma thinks the
Single Breath Disease Diagnostics Breathalyzer has the potential to
empower individuals to take care of their own health like never before.
“People can get something over the counter and it’s going to be a first
response or first detection type of device. This is really a
nanomedicine application that is affordable because it is based on
inexpensive ceramic materials that can be mass produced at low cost,”
she notes.

The
manufacturing process that creates the single crystal nanowires is
called “electrospinning.” It starts with a liquid compound being shot
from a syringe into an electrical field. The electric field crystallizes
the inserted liquid into a tiny thread or “wire” that collects onto an
aluminum backing. Gouma says enough nanowire can be produced in one
syringe to stretch from her lab in Stony Brook, N.Y. to the moon and
still be a single grain (monocrystal).

“There
can be different types of nanowires, each with a tailored arrangement
of metal and oxygen atoms along their configuration, so as to capture a
particular compound,” explains Gouma. “For example, some nanowires might
be able to capture ammonia molecules, while others capture just acetone
and others just the nitric oxide. Each of these biomarkers signal a
specific disease or metabolic malfunction so a distinct diagnostic
breathalyzer can be designed.”

“This
concept could not have been realized without a fundamental
understanding of the material used to create the miniaturized gas
detectors,” said Janice Hicks, a deputy division director in the
Mathematical and Physical Sciences Directorate at NSF. “The research
transcends traditional scientific and engineering disciplines and may
lead to new applications or diagnostics.”

Gouma
also says the nanowires can be rigged to detect infectious viruses and
microbes like Salmonella, E. coli or even anthrax. “There will be so
many other applications we haven’t envisioned. It’s very exciting; it’s a
whole new world,” she says.

Source: National Science Foundation