Monitoring Glucose Levels Without Needles

Typically, glucose levels are monitored via blood samples, which requires the use of needles every time the procedure is done. Noninvasive glucose monitoring devices are not currently available in the US, so users are forced to use blood samples to measure sugar levels; however, those days could be over with a breakthrough from researchers at Penn State. In a recently published paper, the team outlines how they developed a noninvasive, wearable sensor that can monitor glucose levels in the user's sweat.

The engineers designed the sensor using laser-induced graphene (LIG), a material consisting of atom-thick carbon layers in various shapes and offers high electrical conductivity. It also has a fabrication time of just seconds, making it an ideal material for sensing applications. The only problem is that graphene is not sensitive to glucose, meaning it will need another material to detect sugar levels. The researchers chose nickel for its excellent glucose properties and combined it with gold, lowering the risk for allergic reactions. It's those combinations that allow the sensor to sense glucose levels in sweat on the skin's surface.

Although blood has a higher concentration, the sensor is sensitive enough to accurately measure the monosaccharide in sweat and reflect those concentrations in blood. In testing, the researchers used a skin-safe adhesive on a participant to measure levels one hour and three hours after eating a meal. The participant then performed a brief workout to produce sweat at both time intervals, and the researchers found that glucose levels decreased concentration levels from one test to the other. They then compared their results with those taken conventionally through blood tests and found they were nearly identical. The team plans to improve their prototype for future applications, including continuous monitoring of glucose levels and treatment actions, such as administering insulin.