Nano Ink 'Tattoo' Could Monitor Diabetes

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I'm going to be trying to post scientific news from around the web as I find it.

This article was posted on the Discovery Channel Discovery News.

Controlling your diabetes could make you look tough.

A special tattoo ink that changes color based on glucose levels inside the skin is under development by Massachusetts-based Draper Laboratories. The injectable nanotech ink could eventually free diabetics from painful blood glucose tests.

"It doesn't have to be a large, over-the-shoulder kind of tattoo," said Heather Clark, a scientist at Draper. "It would only have to be a few millimeters in size and wouldn't have to go as deep as a normal tattoo."

Clark and her colleagues didn't set out to create a glucose-detecting ink.

"At first I didn't even think it was possible," said Clark.

Originally the scientists developed a sodium-sensitive ink to monitor heart health, advancing basic knowledge of electrolytes in the body, or to ensure athletes are properly hydrated.

Monitoring a single ion is easier than a complex molecule made of 24 atoms however. After speaking with a colleague, Clark decided to give glucose detection a try.

She started with the basic three-part system to detect sodium and modified to detect glucose. The nano ink particles are tiny, squishy spheres about 120 nanometers across. Inside the sphere are three parts: the glucose detecting molecule, a color-changing dye, and another molecule that mimics glucose. When the particles are dissolved in water they look like food coloring, says Clark.

The three parts continuously move around the inside the hydrophobic orb. When they approach the surface, the glucose detecting molecule either grabs a molecule of glucose or the mimicking molecule.

If the molecules mostly latch onto glucose, the ink appears yellow. If glucose levels are low, the molecule latches onto the glucose mimic, turning the ink purple. A healthy level of glucose has a "funny orangey," color, according to Clark. The sampling process repeats itself every few milliseconds.

Time measured in milliseconds is much faster than then most current blood testing systems, and certainly less painful. But is it as accurate?

More at: http://dsc.discovery.com/news/2009/0...es-tattoo.html