New Sensor Measures Glucose in Eye Tears for Integration Into Contact Lenses

Scientists at Oregon State University have developed a tiny sensor that can measure the concentration of glucose in tears, and may one day be integrated into contact lenses for noninvasive glucometry.

The sensor relies on an amorphous indium gallium oxide field effect transistor, or IGZO FET, which can be connected to an external display device or insulin pump to create a more comprehensive diabetes management system.

The sensor itself is essentially transparent, but there’s still a great deal of work left to be able to integrate it into a contact lens and be able to receive its readings. Nevertheless, we hope that the hardest part has been overcome and the remaining technical challenges will be conquered quickly. Certainly just about everyone with diabetes would love a way to measure blood glucose levels without having to prick themselves.

From the study abstract in journal Nanoscale:

Continuous monitoring of the drain–source current indicates a stepwise and fully reversible response to glucose concentrations with a short response time. The specific catalytic reaction between the GOx enzyme and glucose eliminates interference from acetaminophen/ascorbic acid. We demonstrate that nanostructured IGZO FETs have improved sensitivity compared to non-nanostructured IGZO for sensing glucose and can be potentially extended to other biosensor technologies.