Aug 4 2020
In collaboration with partners in healthcare and industry, researchers from the Fraunhofer Institute for Reliability and Microintegration IZM have developed a graphene oxide-based sensor system that can identify acute infections such as sepsis or the antibodies against the coronavirus within a few minutes.
Fraunhofer researchers are developing graphene oxide-based biosensors to detect bacterial and viral infections within just 15 minutes. Image Credit: © Fraunhofer IZM.
The present COVID-19 pandemic situation highlights the significance of identifying infections accurately and quickly to avoid further spread. At present, symptoms are the clues used to diagnose bacterial or viral infections.
But several infections exhibit similar symptoms. Thus, these signs could easily be misread, leading to misdiagnosis of the disease. Although blood tests ensure certainty, laboratories perform these only when prescribed by the family physician. Moreover, before the results are obtained from the lab, doctors usually prescribe an antibiotic that could be unnecessary.
Just One Drop of Blood for a Diagnosis
At the Fraunhofer IZM in Berlin, scientists have been working on the Graph-POC project since April 2018, which involves developing a graphene oxide-based sensor platform to address exactly these difficulties in the diagnosis of infections.
Only a single drop of saliva or blood is required to carry out an accurate analysis. A few minutes after applying the drop to the surface of the sensor, the test result is conveyed as electrical signals to the family doctor’s office.
This quick test offers certainty in just 15 minutes to substitute the protracted blood work in the lab. It eliminates the guesswork and error out of diagnosis, thereby enabling the physician to prescribe the suitable treatment or appropriate antibiotics.
Moreover, the test could be configured to identify antibodies that exist even after a patient recovers from an infection. The Fraunhofer IZM team is now focusing on this application to identify earlier infections caused by the COVID-19 virus, which could be helpful in the attempts to trace the mode of spread of the infection.
When an infection occurs, the human body forms proteins or molecules named biomarkers as a response. Molecules placed on the graphene-based sensor’s surface could help detect these biomarkers. The occurrence of infection can be determined through differential measurements of the concentration of the biomarkers.
3D Structure to Enlarge the Measuring Surface
The most fascinating aspect of this sensor platform is its base material: Graphene oxide is not just biocompatible and electrically conductive but also a highly reliable means of detection. Until now, it has been used in its original form, a 2D monolayer, only in microelectronics.
The Fraunhofer IZM team is now using it in a 3D structure in the form of flakes. This 3D form improves the measuring surface, and thus the accuracy of measurements.
We can pivot from the current medical field to also develop in the direction of the point of need; that is, towards environmental technology and the detection of environmental impacts. But of course the corona application is our first priority.
Manuel Bäuscher, Scientist, Fraunhofer IZM
Bäuscher, who is also a sub-project manager at Graph-POC, envisions higher prospects for these graphene oxide sensors in the future.
The 3D array and heightened sensitivity of the graphene oxide flakes also pave the way for further applications. For instance, it could sense harmful gases like acetone or carbon monoxide even at ambient temperature.
However, currently, these gases must be first heated to initiate a surface reaction that can be detected by the existing sensors. At lower temperatures, the graphene oxide sensor reacts through the bonding of the metal oxides with its sensitive surface.
The Fraunhofer IZM team is making efforts to address another challenge of scaling up the production process to enable mass manufacturing: They are seeking to use the graphene oxide coating at the wafer level to enable processing of hundreds of chips at the same time.
Antibodies Detectable After Coronavirus Infections in About One Year
Before deploying the rapid tests, it is essential to integrate the graphene oxide-based sensors into a plastic carrier and to test the system’s reliability. The original project to identify infections has been scheduled to work until spring 2021, but the researchers predict that the sensor cannot be verified for the coronavirus for another year.
The Charité, Aptarion Biotech AG, Technische Universität Berlin, MicroDiscovery GmbH, and alpha-board GmbH are the collaborators in this project. The study is financially supported by the German Federal Ministry of Education and Research (BMBF).