ETH researchers led by Raffaele Mezzenga have developed a new diagnostic method. It is based on Birefringence, the ability of substances to change the polarisation state of light. With this method, doctors around the world can easily, rapidly and reliably detect malaria, Ebola or HIV to name only a few.
Nothing could be simpler: a drop of blood is placed on a special carrier substance; after a wait of a few minutes, the slide is placed on a device that emits polarised light thanks to an inexpensive polarisation filter. It is covered with a lid containing a second polarisation filter, which blocks the light from all materials except crystalline or materials with directional properties. If light is visible through the cross-polariser filter, a positive diagnosis is made. Through this an immediate ‘yes or no’ screening is possible. It is also possible to measure the light intensity, and thus the amount of the pathogen, through a simple light meter plugged into a smartphone and controlled via an app.
Read more: Diagnostics with birefringence