Diabetes Tattoo?

According to this article, researchers are looking into a nano ink that changes colors according to blood glucose levels.

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.

This sounds awesome to me, but then again, I already have a tattoo, so I wouldn't mind getting another. I can't wait to find out more.