Soon, breathalyser to detect and monitor diabetes

Scientists have developed a new sensor technology that could make it possible to diagnose and monitor diabetes through a breath analysis alone.
Diabetes patients often receive their diagnosis after a series of glucose-related blood tests in hospital settings, and then have to monitor their condition daily through expensive, invasive methods.
Chemists at the University of Pittsburgh have demonstrated a sensor technology that could simplify the diagnosis and monitoring of diabetes through breath analysis alone.
Even before blood tests are administered, those with diabetes often recognise the condition's symptoms through their breath acetone - a characteristic "fruity" odour that increases significantly with high glucose levels.

The Pitt team was interested in this biomarker as a possible diagnostic tool.
"Once patients are diagnosed with diabetes, they have to monitor their condition for the rest of their lives," said Alexander Star, principal investigator of the project and Pitt associate professor of chemistry.

"Current monitoring devices are mostly based on blood glucose analysis, so the development of alternative devices that are noninvasive, inexpensive, and provide easy-to-use breath analysis could completely change the paradigm of self-monitoring diabetes," he said.
Star and colleagues used what's called a "sol-gel approach," a method for using small molecules (often on a nanoscale level) to produce solid materials.

The team combined titanium dioxide - an inorganic compound widely used in body-care products such as makeup - with carbon nanotubes, which acted as "skewers" to hold the particles together.
These nanotubes were used because they are stronger than steel and smaller than any element of silicon-based electronics.
This method, which the researchers playfully call "titanium dioxide on a stick," effectively combined the electrical properties of the tubes with the light-illuminating powers of the titanium dioxide.
They then created the sensor device by using these materials as an electrical semiconductor, measuring its electrical resistance (the sensor's signal).
The researchers found the sensor could be activated with light to produce an electrical charge. This prompted them to "cook" the "skewers" in the sensor under ultraviolet light to measure acetone vapours - which they found were lower than previously reported sensitivities.

"Our measurements have excellent detection capabilities. If such a sensor could be developed and commercialised, it could transform the way patients with diabetes monitor their glucose levels," Star said.
The team is currently working on a prototype of the sensor, with plans to test it on human breath samples soon.
The study was published in the Journal of the American Chemical Society (JACS).