The technique could eliminate the need for diabetics to draw blood to heck their glucose levels. The biochip uses plasmonicinterferometers and could be used to measure a range of biological and environmental substances. 

For the 26 million Americans with diabetes, drawing blood is the most prevalent way to check glucose levels. It is invasive and at least minimally painful. Researchers at Brown University are working on a new sensor that can check blood sugar levels by measuring glucose concentrations in saliva instead.

Tripping the light fantastic. Each plasmonic interferometer – thousands of them per square millimeter – consists of a slit flanked by two grooves etched in a silver metal film. The schematic shows glucose molecules “dancing” on the sensor surface illuminated by light with different colors. Changes in light intensity transmitted through the slit of each plasmonic interferometer yield information about the concentration of glucose molecules in solution. (Credit: Domenico Pacifici)