Sweat-Sensing Glucose Monitor Could Put an End to Regular Finger Prick Pains

Researchers at the University of California San Diego have published a paper detailing a needle-free approach to accurately monitoring blood glucose levels, analyzing the user's sweat rather than their blood.

"Diabetes prevalence has been rising exponentially, increasing the need for reliable non-invasive approaches for glucose monitoring," the three researchers explain in their paper's abstract. "Different biofluids have been explored recently for replacing current blood finger-stick glucose strips with non-invasive painless sensing devices."

"While sweat has received considerable attention, there are mixed reports on correlating the sweat results with blood glucose levels. Here, we demonstrate a new rapid and reliable approach that combines a simple touch-based fingertip sweat electrochemical sensor with a new algorithm that addresses for personal variations toward the accurate estimate of blood glucose concentrations."

Based on a polyvinyl alcohol hydrogel atop an electrochemical sensor, itself screen-printed onto a flexible plastic strip, the sensor only needs to be in contact with the surface of a finger for one minute to capture enough sweat to trigger an enzymatic reaction. When introduced to a small handheld analyzer, the resulting minute electrical current can be detected - and used to gauge the user's blood glucose level.

The dream of a needle-free future for blood glucose monitoring, though, isn't quite realized: While the device proved accurate, it requires training against a traditional finger prick test — though this would only need to be carried out once or twice a month, dramatically reducing the number of blood samples required.

The team's work has been published in the journal ACS Sensors under closed-access terms.

Article main image adapted from ACS Sensors 2021, DOI: 10.1021/acssensors.1c00139.