New diabetes device developed that checks saliva instead of blood

A new device developed by scientists in the United States measures blood sugar levels in saliva, so that diabetics do not have to draw blood when checking their levels.
The study, published in the journal Nano Letters, involved thousands of plasmonic interferometers being etched onto a biochip that was then able to measure the concentration of glucose molecules in water. Small alterations in the intensity of the light passing through the slit of each plasmonic interferometer provides data on the concentration of glucose molecules in solution.
The slits that capture incoming light photons and confine them are only around 100 nanometers wide, with a couple of 200 nanometer-wide grooves on either side. The grooves scatter the photons so that they interact with the free electrons moving on the metal surface of the sensor.
It was found that the biochip could detect glucose levels similar to the levels found in human saliva, which is usually around 100 times less concentrated than in the blood. It is hoped the breakthrough will also offer measurements of a variety of biological, chemical and environmental substances.
Lead author Domenico Pacifici commented “This is proof of concept that plasmonic interferometers can be used to detect molecules in low concentrations, using a footprint that is ten times smaller than a human hair.” The researchers now hope to build sensors specifically for glucose and other substances and carry out more tests on the device.