Holograms for molecules

Scientists at ETH Zurich and the company Roche have

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jointly developed a completely new analysis method based on light diffraction on molecules on a small chip. The technique has the potential to revolutionise diagnostics: in future, physicians may be able to perform complex examinations easily and quickly in their own practice.

Directly visible with laser light

As with other established diagnostic procedures, the new method also uses the key-lock principle of molecular recognition: for instance, in order to determine a particular protein dissolved in the blood (the "key"), it must dock on to a suitable antibody (the "lock"). In established immunological test methods, the "key in the lock" is made visible with a second colour-coded key, but this step is no longer necessary in the new process - the "key in the lock" can be made visible directly with a laser light.

The scientists use a chip with a specially coated surface made up of tiny dots with a specific striped pattern. The molecules in question bind to the stripes but not to the interstices between the stripes. If a laser light is now directed along the chip's surface, it is bent (diffracted) as a result of the special arrangement of the molecules in the pattern and focused on to a point below the chip. A point of light becomes visible. When the scientists put samples without the molecules on to the chip, the light is not bent and no point of light is visible.

Read more at: https://phys.org/news/2017-09-holograms-molecules.html#jCp