Copper film can detect glucose levels from body sweat

Managing diabetes could become much cheaper and simpler as researchers in Australia have developed a copper film that can detect glucose from body fluids containing salt, such as sweat or tears.

Researchers at the University of Wollongong's (UOW) Institute for Superconducting and Electronic Materials (ISEM) reported demonstration of the first construction of copper with a sponge-like porous structure, which can quickly and accurately detect glucose in salt-based fluids.

"The sponge-like porous structure greatly increases the surface area and therefore enhances the sensitivity required to trigger an electrochemical signal," said Professor Yusuke Yamauchi.

"The extraordinary sensing performance of the copper film is probably attributed to its intrinsically good reaction toward glucose oxidation," Yamauchi noted.

"This makes this copper film a good candidate for the direct detection of glucose to satisfy the requirements of diverse applications, such as diabetes management," he added.

People with diabetes often have low levels of insulin, a hormone that converts sugars to energy, which means they have to closely watch their glucose or blood-sugar levels to prevent further chronic health complications.

Foods, physical activity and other factors can influence glucose levels.

This has led medical device manufactures toward developing continuous glucose monitors that can be inserted just under the skin, providing the wearer with regular blood-sugar readings, removing the need for regular finger-pricking to extract a drop of blood for sugar measurement.

But the technology remains expensive, mainly due to the use of precious metals such as platinum in the sensor.

"Precious metals such as gold and platinum have very good conductivity but they are very expensive and we wanted to focus on more abundant and cheaper metals," Yamauchi said.

So the researchers developed a porous copper film with the sponge-like structure.

Testing revealed the film has high selectivity, reacting to glucose without interference from other acids and sugars that can be present in sweat, said the study published in the journal Angewandte Chemie.

The researchers believe the copper film could be integrated into a wearable sensor or a smartwatch, providing continual glucose readings to the wearer, which could also be sent via wireless to their doctor.