New York: Scientists have developed a self-powered paper-based wearable sensor that can allow diabetics to measure glucose levels from sweat during exercise.

Today's most widespread methods for glucose self-testing involve monitoring glucose levels in blood. Conventional measurements, however, are not suitable for preventing hypoglycemia during exercise, said Seokheun Choi, Assistant Professor at Binghamton University, State University of New York in the US.

The process of measuring blood glucose levels include pricking the skin to take blood samples. Doing this during exercise may cause the blood to get contaminated with excess sweat, or lead to skin irritation, Choi said. "The method needs patients to carry many accessories during physical activity, including lancets, alcohol swabs and a relatively large glucometer," she added.

Researchers have developed and demonstrated a self-powered, wearable and disposable patch that allows for non-invasive monitoring of glucose in human sweat. This wearable, single-use biosensor integrates a vertically stacked, paper-based glucose/oxygen enzymatic fuel cell into a standard Band-Aid adhesive patch. "The paper-based device attaches directly to skin, wicks sweat to a reservoir where chemical energy is converted to electrical energy, and monitors glucose without external power and sophisticated readout instruments," said Choi.

Sweat-based glucose sensing is attractive for managing exercise-induced hypoglycemia because the measurement is performed during or immediately after exercise when there is enough sweat to obtain an adequate sample, said Choi.

This potential alleviates shortcomings of conventional non-invasive sweat sensors, which can be hampered by the difficulty of collecting enough sweat for analysis, sample evaporation and the relatively long time required for sample collection. "The sensing platform holds considerable promise for efficient diabetes management, and a fully integrated system with a simple readout can be realised toward continuous non-invasive glucose monitoring," researchers said.

The research was published in the journal Micromachines.