US scientists at Brown University have developed a new biochip sensor to detect blood sugar via saliva.
The advance is an important step towards a device that would enable people with diabetes to test their glucose levels without drawing blood.
The biochip is made from a one-inch-square piece of quartz coated with a thin layer of silver. Etched in the silver are thousands of nanoscale interferometers tiny slits with a groove on each side.
The new chip makes use of a series of specific chemical reactions combined with plasmonic interferometry, a means of detecting chemical signature of compounds using light.
The device is sensitive enough to detect differences in glucose concentrations that amount to just a few thousand molecules in the sampled volume. The grooves measure 200 nanometers wide, and the slit is 100 nanometers wide about 1000 times thinner than a human hair.
Who: US scientists
Where: Brown University