Tuneable graphene nano sensor has host of applications claim researchers

Developed by a team from Swiss research University EPFL (École Polytechnique Fédérale de Lausanne) and the Institute of Photonic Sciences in Barcelona, the device is claimed to have significant advantages over infrared absorption spectroscopy, the most commonly used molecule detection method.

This existing technique uses light to excite molecules, which can then be identified courtesy of their unique vibration signature.  However, whilst it’s effective for larger molecules, the wavelength of an infrared photon (around 6,000 nanometres) means that it struggles to detect the vibration of nano-scale molecules.

In an effort to improve on this technique the team turned to graphene and began by creating a pattern of nanostructures on the surface of the graphene by bombarding it with electron beams and etching it with oxygen ions.

When exposed to light, electrons in these nanostructures began to oscillate, and this phenomenon concentrates light into tiny spots, which are comparable with the dimensions of the target molecules. According to the group, it is then possible to detect nanometric compounds in proximity to the surface.