Single unlabelled biomolecules can be detected through light
Being able to track individual biomolecules and observe them at work is every biochemist's dream. This would enable the scientists to research in detail and better understand the workings of the nanomachines of life, such as ribosomes and DNA polymerases. Researchers at the Max Planck Institute for the Science of Light have taken a big step closer to this goal. Using an optical microstructure and gold nanoparticles, they have amplified the interaction of light with DNA to the extent that they can now track interactions between individual DNA molecule segments. In doing so, they have approached the limits of what is physically possible. Their optical biosensor for single unlabelled molecules could also be a breakthrough in the development of biochips: fingernail-size mini-labs in mobile analytical devices could test a drop of blood for multiple diseases simultaneously or facilitate comprehensive environmental analyses with very little sample material.