Tattoos to help diabetics monitor blood sugar

Tattoos one day may be more than just a piece of artwork on the body as scientists are developing a carbon nanotube ink capable of monitoring glucose levels in type I diabetics.

People with type I diabetes currently have to prink their fingers several times a day to test their blood sugar levels – the pain is minor, but the chore interferes with daily life. The finger prick test is the most accurate test, but scientists at MIT are hoping to create precise wearable devices which eliminate the need for testing blood.

“Diabetes in an enormous problem, global in scope, and despite decades of engineering advances, our ability to accurately measure glucose in the human body still remains quite primitive,” said Michael Strano, professor of chemical engineering at MIT.

Strano has been developing a novel ink capable of detecting glucose levels with postdoctoral researcher Paul Barone. The ink consists of carbon nanotubes wrapped in a polymer which is sensitive to glucose concentrations. The nanotubes suspended in a saline solution, which can be injected into the skin like a tattoo.
When the sensor – a device similar to a wristwatch worn over the tattoo – encounters glucose, the nanotubes fluoresce and can be detected by shining near-infra-red light on them. Measuring the amount of fluorescence reveals the concentration of glucose.

One advantage of this type of sensor is that the carbon nanotubes are not destroyed by light exposure, unlike some fluorescent molecules, although the tattoo would need to be ‘refreshed’ after a specified length of time.
Barone and Strano are now working on improving the accuracy of their sensor and may begin trials in animals shortly.