Researchers from Draper Laboratories have developed an injectable nanosensor that can be injected into the skin to monitor an individual's blood-sugar level.

The material consists of 120-nanometer polymer beads coated with a biocompatible material. Within each bead is a fluorescent dye and specialized sensor molecules, designed to detect specific chemicals, such as sodium or glucose.

When injected into the skin, the sensor molecule pulls the target chemical-say, sodium-into the polymer from the interstitial fluid, which surrounds cells. 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. Scientists can swap in different recognition molecules to measure different targets, including chloride, calcium, and glucose. The range of concentrations that the sensor can detect can be varied by altering the ratio of the components, depending on whether it is important to measure precise concentrations or more broad variability.

The sodium sensor has already been tested in animal trials with promising results; the glucose sensor works in vitro but but has yet to be tested in animal trials. Obviously more studies needs to be done, but the technology promises a cheaper, more convenient and less invasive mode of glucose or sodium monitoring.

Photo Credit: Heather Clark, Draper via Technology Review