Collaborative Technology Demonstrates Potential in Diabetes Testing
Diabetes is a disease afflicting tens of millions of people. Current diagnostic testing can include expensive doctor’s visits and invasive testing, which makes diagnosing and monitoring the disease anything but straightforward. One symptom of diabetes is “fruity” breath, which may occur when the body cannot produce or use insulin effectively.
Glucose is our body’s main source of energy, but when deprived of this fuel – as in diabetics – it turns to the next best thing, fat. Fat metabolism results in the body producing ketones, specifically acetone, which is associated with side effects including fruity-smelling breath. While everyone produces a certain level of acetone through normal, daily metabolic processes, diabetics produce it in larger amounts and also exhale it at a higher rate than non-diabetics, which is what produces the “fruity” aroma that indicates high blood glucose levels.
A recent R&D innovation from the National Energy Technology Laboratory and its Regional University Alliance (NETL-RUA) has the potential to simplify diagnosis of diabetes through acetone detection. The NETL-RUA has developed a new hybrid nanostructure material that may be used in an inexpensive “breathalyzer” to test for and monitor diabetes.
The word breathalyzer provokes images of testing for intoxicated driving. But in fact, the new technology would be used in breathalyzers to monitor blood sugar, rather than blood alcohol. When used as a sensing tool in a breath analyzer, the NETL-RUA hybrid nanostructure could offer a way for millions of diabetics to trade the pain and hassle of finger sticks for a non-invasive testing solution.
|An illustration of (left) an acetone molecule adsorbed on a titanium dioxide cluster at the surface of a carbon nanotube, and (right) a hypothetical diabetes breathalyzer device.
NETL-RUA researchers discovered that by bolstering titanium dioxide—the same ingredient found in most sunscreens—with carbon nanotubes, or CNTs, they could produce a sensor that can detect acetone vapors at parts per million levels. Carbon nanotube (CNT)-based sensors are extremely small, inexpensive, consume little to no power, and are compatible with complementary metal-oxide-semiconductor (CMOS) technology, which allows further incorporation into modern electronic devices, like smart phones. These advantages make CNT-based sensors ideal for chemical sensing and non-invasive medical diagnostic tools.
CNTs are also highly conductive. Titanium dioxide is highly refractive and highly absorbent to UV rays. The research team combined titanium dioxide with CNTs to form a hybrid nanostructure, which was deposited on a silicon substrate with gold contacts for testing. When exposed to UV light and acetone vapor, the electrical conductivity of the hybrid decreased as acetone concentrations increased from 2 to 20 parts per million (ppm); researchers also calculated the detection limit of the hybrid material at 0.4 ppm acetone. The sensitivity and electrical response are in a useful range for diagnosis and monitoring of diabetes.
The NETL-RUA team—Alexander Star, principal investigator and an associate professor of chemistry at University of Pittsburgh; Dan Sorescu, a research physicist at the National Energy Technology Laboratory; and Mengning Ding, a Pitt graduate student in chemistry—are now developing a prototype sensor. Successful tests on human breath samples could mean a game-changing medical technology is on the way. It is anticipated that the portable sensors could facilitate the diabetes research and clinical practice related to this disease.
Contact: Dan Sorescu, 412-386-4827