A new diagnostic test developed by researchers at ETH Zurich can tell if a patient has Type I diabetes, but gone are the days of blood samples and lab work. The new nanotech sensor can tell instantly if a patient has diabetes or an associated complication called diabetic ketoacidosis by simply analyzing a sample of exhaled breath.

The sensor — a breathalyzer of sorts for diabetes — scans the breath for high levels of acetone, a biomarker associated with Type I diabetes. If an exceptionally high level of acetone is detected, it’s a strong indicator that the person is suffering from ketoacidosis, a potentially serious buildup of acetone in the blood that occurs when insulin levels fall too low.

The sensor takes advantage of a the properties of tiny ceramic nanoparticles that are laid in a thin film between two gold electrodes inside the device. Those particles act like a kind of electrical resistor, but when acetone comes in contact with the sensor that resistance is diminished. Small amounts of acetone don’t drastically affect the sensor, but in doses indicative of diabetes the resistance is noticeably altered, allowing electricity to flow between the electrodes more freely and raising red flags. The higher the acetone level, the redder the flag.

With sensitivity at 20 parts acetone per billion, the sensor can detect acetone at levels 90 times lower than that found in the breath of diabetics, so the chance of it missing a diagnosis is very low. It could provide emergency room techs a quick diagnostic tool with which to determine if a diabetic patient has developed ketoacidosis. But it has more practical uses as well; as costs come down, it could be used by diabetics in the home to determine if they need to take more insulin, skirting the problem of ketoacidosis altogether.

Science Daily