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Biosensoren auf Graphenoxidbasis e1640176615297

Together with project partners, Fraunhofer IZM researchers are developing a handy graphene oxide-based sensor platform that will make it possible to detect acute infections such as sepsis or antibodies against the coronavirus in just a few minutes.

One Drop of Blood is Sufficient for Diagnosis

It is not only the current situation of the COVID 19 pandemic that shows how important it is to detect infections quickly and accurately so that further infections can be prevented. Diagnoses of viral or bacterial infections are often made on the basis of symptoms. This can quickly lead to misinterpretations, as some infections cause similar courses of disease. Blood tests provide certainty, but are only carried out in laboratories on the prescription of the general practitioner. By the time the results of the analysis arrive, an antibiotic that may not be necessary is often already prescribed.

Since April 2018, researchers at the Fraunhofer Institute for Reliability and Microintegration IZM in Berlin have been working on a graphene oxide-based sensor platform in the Graph-POC project, which aims to solve precisely these challenges in the diagnosis of infections.

Only one drop of blood or saliva should be necessary to perform an accurate analysis. The drop is placed on the sensor surface, and within a few minutes a result communicated via electrical signals appears – at the family doctor’s office, according to the scientists. According to the researchers, lengthy laboratory tests of the blood would thus be replaced by a rapid test that would provide certainty within just 15 minutes. An appropriate form of treatment or suitable antibiotics could then be prescribed.

Antibodies also in Focus

The test could also be designed to detect antibodies in the case of an infection that has already occurred. Fraunhofer IZM researchers are currently focusing on this application in order to detect previous infections with the COVID-19 virus and thus, for example, to identify infection pathways.

Since the human body produces certain molecules or proteins during an infection that can be used as biomarkers, capture molecules are placed on the sensor surface of the graphene oxide-based platform to detect them. Whether an infection is present is then determined by differential measurements on the concentration of the biomarkers, he said.

Graphene Oxide in 3-D Structure in the Form of Flakes

The special feature of the sensor platform is the material used: graphene oxide is particularly distinguished by the fact that it is an electrically conductive and biocompatible material and allows particularly reliable detection. In microelectronics, it has so far only been used in its original 2-D form.

However, the Fraunhofer IZM researchers are now applying it in a 3-D structure in the form of flakes. This three-dimensional shape increases the measurement area and also the accuracy of the measurements, the scientists emphasize.

Corona Application Has Priority

Manuel Bäuscher, a scientist at Fraunhofer IZM and subproject leader of the Graph-POC project funded by the German Federal Ministry of Education and Research BMBF, sees great prospects in graphene oxide sensors: “From the current medical field, we can also develop into the so-called point of need, i.e. toward environmental technology and the detection of environmental influences. But first, of course, the corona application has priority.”

The 3-D arrangement of the graphene oxide flakes and the resulting sensitivity also open up other applications. For example, harmful gases such as carbon monoxide or acetone could be detected even at room temperature. For current sensors of this type, the gases must first be heated so that a surface reaction can take place. By combining the metal oxides with the sensitive surface of the graphene sensor, however, it reacts even at lower temperatures.

Antibody Detection After Coronavirus Infection in About a Year?

In order to scale up the manufacturing process for mass production, the Fraunhofer IZM researchers are tackling another challenge: The coating with graphene oxide should happen at wafer level, so that hundreds of chips could be processed at once.

Until the rapid tests are ready for application, the graphene oxide-based sensors must be embedded in a plastic carrier and the reliability of the system tested. Regularly, the project runs until spring 2021 with regard to the detection of infections, but the scientists expect that verification of the sensor with regard to the coronavirus cannot take place for another year.

Participating project partners are Charité, Aptarion Biotech AG, Technische Universität Berlin, MicroDiscovery GmbH and alpha-board GmbH. The project is funded by the German Federal Ministry of Education and Research BMBF.