Scientists at University of Texas at Dallas have developed a skin sensor that can measure glucose levels in a person’s sweat. Currently, diabetics only use blood samples to quantify their glucose levels. Pricking one’s fingers to draw a sample is painful, and children with diabetes almost universally hate doing it. Many adults regularly guesstimate their own levels to avoid finger pricks. Therefore, being able to accurately measure glucose can go a long way to helping manage diabetes while avoiding the traumatic experience that blood sampling can be for many folks.
The sensor from UT Dallas was developed to be able to use very small amounts of sweat, less than a microliter, which would make it practical for integration into wrist trackers and other body-worn devices. It is made of a readily available polymer-based textile and relies on the same enzymatic reaction that powers existing blood-based glucometers.
The design of the sensor optimizes how sweat spreads through it so that the liquid covers the entire surface of the device. The surface itself features a novel topography that helps grab onto glucose oxidase molecules, improving the sensitivity of the sensor.
Overall, the device addresses a few critical issues of sweat-based glucose testing, such as changes in the skin’s pH levels and errors that arise from other compounds that end up under the sensor.
Some details from the study abstract:
The novel device comprises of stacked metal/metal-oxide (gold/zinc oxide) thin films within porous polyamide substrates for low-volume ultrasensitive impedance based detection of glucose and cortisol using non-faradaic electron-ionic charge transfer. In this work, we report the detection of glucose over a concentration range from 0.01–200 mg/dL spiked in synthetic and human sweat. Monoclonal antibodies specific to glucose oxidase were immobilized on thiolated ZnO sensing electrode surfaces resulting in the modulation of charge transfer within the electrical double layer (EDL). Non-Faradaic electrochemical impedance spectroscopy (EIS) was used to calibrate the sensor response with varying dose concentration through measurement of change in impedance. Reliable limit of detection (LOD) of 0.1 mg/dL in human sweat was demonstrated.
Study in journal Sensors and Actuators B: Chemical: Lancet-free and label-free diagnostics of glucose in sweat using Zinc Oxide based flexible bioelectronics…