Nanosensing and biochemistry

This is not really new…but it was new to me today when I found some articles on this innovative technology. I am talking about a nanosensor that could be injected into the skin, much like tattoo dye, to monitor an individual's gluclose level. As the glucose level increases, the dye would fluoresce under an infrared light.

The researchers at Draper Laboratory, in Cambridge (MA), have already tested a sodium-sensing version of the device in mice, and are due to begin animal tests of the glucose-specific sensor.

The material consists of 120-nanometer polymer beads coated with a biocompatible material. A patent application has been filed. Within each bead is a fluorescent dye and specialized sensor molecules, designed to detect specific chemicals (so far the work has been done on sodium and glucose).

When injected into the skin, the sensor molecule pulls the target chemical into the polymer from the interstitial fluid. To compensate for the newly acquired positive charge of a sodium ion, a dye molecule releases a positive ion, making the molecule fluoresce. The level of fluorescence increases with the concentration of the chemical target.  The range of concentrations that the sensor can detect can apparently be varied, depending on whether it is important to measure precise concentrations or more broad variability.

The sodium sensor has shown early success in animals. The researchers have developed a glucose sensor that works via a similar mechanism. It has been shown to work in a solution but has not yet been tested in animals.

Still, the researchers have a long way to go before the sensor is ready for human testing. However, if it works and it is accessible, this could be a good way to make a good use of a tattoo :-)