The University of Göttingen, Researchers have developed a brand new technique that takes advantage of the unique characteristics of graphene to interact with fluorescing molecules electromagnetically. This technique allows scientists for the first time – to optically measure tiny distances, within the order of 1 ångström (one ten-billionth of a meter) with highest precision and reproducibility. These enabled researchers to optically measure the thickness of lipid bilayers, the stuff that makes the membranes of all residing cells. The results were published in Nature Photonics.
Researchers from the University of Göttingen led by Professor Enderlein used a single sheet of graphene, only one atom thick (0.34 nm), to modulate the emission of light-emitting (fluorescent) molecules when they got here near the graphene sheet. The superior optical transparency of graphene and its capability to accentuate by space the molecules’ emission made it a susceptible software for measuring the area of single molecules from the graphene sheet. The accuracy of this technique is so good that even the slightest distance modifications of around 1 Angstrom could be resolved. The scientists were in the condition to show this by depositing single molecules above a graphene layer. They could then decide their distance by monitoring and evaluating their light emission. This graphene-induced modulation of molecular light emission offers an extremely sensitive and exact “ruler” for determining single-molecule positions in space. They used this method to measure the thickness of single lipid bilayers that are constituted of two layers of fatty acid chain molecules and have a total thickness of only a few nanometers.