If radiation or chemotherapy treatment of leukaemias or lymphomas does not bring sufficient success, the transplantation of bone marrow or blood stem cells is usually the only chance of cure. Unfortunately, the majority of patients die despite transplantation, often due to spontaneous infec ... more
Easy printing of biosensors made of graphene
Cost-effective roll-to-roll production
Cell-based biosensors can simulate the effect of various substances, such as drugs, on the human body in the laboratory. Depending on the measuring principle, though, producing them can be expensive. As a result, they are often not used. Cost factors for sensors that perform measurements electrically are the expensive electrode material and complex production. Fraunhofer scientists are now producing biosensors with graphene electrodes cheaply and simply in roll-to-roll printing. A system prototype for mass production already exists.
Cell-based biosensors measure changes in cell cultures via electrical signals. This is done by means of electrodes which are mounted inside the Petri dish or the wells of a so-called well plate. If added viruses destroy a continuous cell layer on the electrodes, for example, the electrical resistance measured between the electrodes is reduced. In this way, the effect of vaccines or drugs (for example) can be tested: the more effective the active ingredient is, the smaller the number of cells that are destroyed by the viruses and the lower the measured resistance change will be. Also toxicity tests, such as on cosmetic products, can function according to the same principle and may replace animal experiments in the future. Another advantage: If biosensors are linked to an evaluation unit, measurements can be continuous and automated.
Conductive, biocompatible, printable
The preparation of the described biosensors is expensive and complex, though: the electrodes are made of a biocompatible and electrically conductive material, such as gold or platinum. The production of microelectrodes requires a complicated lithographic process. The result: The laboratories often do not buy these biosensors because of the high costs, and the examination of the cell cultures continues to be performed manually under a microscope. As an alternative to precious metals, however, graphene can now be used as a material for the electrodes. The advantages of the carbon material: it is electrically conductive, biocompatible and, if in the form of an ink, can be printed on surfaces.
Scientists at the Fraunhofer Institute for Biomedical Engineering IBMT in St. Ingbert in Germany’s Saarland region have made use of such a graphene ink. Together with industry partners in the M-era.Net project BIOGRAPHY, which is funded by the German Federal Ministry of Education and Research (BMBF), they have developed a printing process which makes it possible to produce large numbers of graphene biosensors in a cost-effective roll-to-roll process. "Our system prototype can print about 400 biosensors per minute on a continuous foil," Dr. Thomas Velten, Head of the Biomedical Microsystems Department at IBMT and Project Manager of BIOGRAPHY, says in describing the result of the development work. While the printing equipment and graphene ink are provided by the partners involved, the scientists at the IBMT have taken care of the design of the printing process. "In particular, it is crucial to adjust parameters such as the ink viscosity, printing speed, doctor blade pressure – a doctor blade wipes off excess ink – and well depth of the printing cylinder so that the printed structures correspond to the nominal dimensions," explains Velten. An interdisciplinary team of biologists and engineers from the IBMT have also developed a protein ink, which is printed directly onto the electrodes after the graphene. Velten: "It’s only thanks to the proteins that the cells adhere well enough to the electrode foil". A complicated process: the surface energies of the foil and ink have to be adapted to one another in such a way that the transfer of the ink from the printing cylinder to the foil takes place optimally. Particularly critical is the drying of the printed structures, since the proteins do not tolerate solvents or high temperatures. Only the right mix of ink ingredients and drying method ensures that the ink will dry quickly enough.
After the successful construction of the prototype, the practical tests of the printed biosensors will follow. Project Manager Velten: "We expect to be able to offer the industry a universal technology platform in no later than a year".
Nanomaterials are already part of everyday life in our modern society. New applications, along with continuously rising quantities being produced, have led to an increased exposure to nanomaterials for both people and the environment. Predicting the behaviour of nanomaterials in organisms a ... more
A wide range of industrially synthesized nanomaterials are present in products we use daily and, in the meantime, are part of our everyday life. Due to their exceptional properties (e. g., increased UV-filtration or stronger adhesion) they are used in clothes, cosmetics, household goods and ... more
What happens when we breathe in nanoparticles emitted by a laser printer, for example? Could these nanoparticles damage the respiratory tract or perhaps even other organs? To answer these questions, Fraunhofer researchers are developing the “NanoCube” exposure device. The Nanocube’s integra ... more
COVID 19 has turned PCR and other antigen tests from tools known only to medical professionals into an everyday experience for all of us. To mark the successful completion of their research on the PoC-BoSens platform, the project consortium led by Fraunhofer IZM can announce the birth of a ... more
A new high-performance white-light laser is expected to speed up quality control in the semiconductor industry and provide closer monitoring of toxicity tests in microbiology. In one step, this laser enables the two-sided characterization of surfaces and can be integrated into production ch ... more
Digitalization and artificial intelligence are changing diagnostics in clinical routine and pharmaceutical research. New IVD devices are coming out, laboratory data is connected to the hospital IT system and AI-based image analysis enables new and efficient processes in digital pathology an ... more
At Fraunhofer IZI-BB we develop analytical and biotechnological solutions for medical issues, animal health, food, cosmetics and the environment. Our research focuses on sample preparation, development of molecular recognition elements and data acquisition as well as miniaturization and aut ... more
- 1Can the AI driving ChatGPT help to detect early signs of Alzheimer's disease?
- 2Simple nasal swab can provide early warning of emerging viruses
- 3Diagnosing cancer in minutes
- 4Holes in T cells
- 5A mobile breakthrough for water environment monitoring
- 6Molecular archeology: 1200-year-old DNA sequences from Madagascar lead to the discovery of an extinct tortoise
- 7Sartorius with clear double-digit growth in fiscal 2022
- 8Bruker Announces Acquisition of ACQUIFER Imaging GmbH
- 9How old is your brain, really?
- 10The architecture of shattered genomes