Sensor Technology Detects Diabetes by Breath Analysis

Physicians often recognize patients with diabetes through the condition's symptoms such as their characteristic breath of acetone, an odor that increases significantly with high glucose levels.

Chemists at the University of Pittsburgh (PA, USA) used a sol-gel approach, a method for using small molecules, often on a nanoscale level, to produce solid materials. The team combined titanium dioxide 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 scientists called "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, which is the sensor's signal. They found the sensor could be activated with light to produce an electrical charge. This prompted them to expose the nanotubes in the sensor under ultraviolet light to measure acetone vapors, which they found were lower than previously reported sensitivities.

The authors concluded that the ultrahigh sensitivity to parts per million (ppm) level of acetone vapors, fast and reversible response, together with miniature size and room temperature operation makes this nanohybrid device a promising sensing platform that could find applications in the detection of breath acetone. The development of a micro-sized low-power electronic breath acetone-sensor device could further benefit personal healthcare by serving as a convenient and low-cost diagnostic tool for diabetes or a novel and high-throughput analytical method in the clinical studies of metabolic disorders.

Alexander Star, PhD, the lead author said, “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. Our measurements have excellent detection capabilities. If such a sensor could be developed and commercialized, it could transform the way patients with diabetes monitor their glucose levels." The study was published on May 21, 2013, in the Journal of the American Chemical Society.

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