Researchers at the Eindhoven University of Technology have developed a quick way to test for infectious diseases. With a special piece of paper, a drop of blood and a camera from your smartphone, for example, you can see within twenty minutes whether you are infected. The research, which was carried out together with Japanese researchers, was published in the journal Angewandte Chemie.

The paper strip used to perform the test lights up and works with a biochemical reaction. “A biochemical reaction causes the paper to emit blue-green light on its underside,” says TU/e professor and research leader Maarten Merkx. “The bluer the colour, the higher the concentration of antibodies. The test shows the presence of infectious diseases by searching for specific antibodies in the blood. These substances make your body react to, for example, viruses and bacteria.

With a digital camera, you can determine the result by reading out the colour. This colour is created by a luminous sensor protein that has been developed at the TU/e. After a blood droplet reaches the paper, this protein triggers a reaction that produces blue light. An enzyme plays a role in this, which also illuminates fireflies and certain fish, for example. In a second step, the blue light is converted into green light. If antibodies bind to the sensor proteins, this second step is blocked. “So you not only know whether the antibody is in the blood but also how much”, Merkx continues.

The researchers have already successfully tested three antibodies simultaneously, namely for HIV, flu and dengue. With this test, expensive and time-consuming lab measurements in the hospital are unnecessary. This creates a lot of potential for the test in developing countries so that it is easy to test for tropical diseases. Merkx expects the test to be on the market within a few years.