Immunoassays are tests that can be used to detect biological substances in a sample. With the emergence of the novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in December 2019 and the resulting global pandemic, the need for rapid virus detection methods became clear.
The established detection methods include lateral flow assays (LFA) and PCR tests, which, however, have serious disadvantages. LFAs test for antibodies in a sample. However, the disadvantage of these so-called rapid tests is their often poor sensitivity and specificity. For specific and highly sensitive detection, PCR tests are used, which test for a nucleotide sequence of the pathogen. However, these require a great deal of time and money, as they can only be carried out by trained personnel and in laboratories equipped for this purpose. We want to counteract these disadvantages as part of our research activities.
At the Institute of Institute for Electrical Measurement Science and Fundamental Electrical Engineering, we are developing detection methods based on magnetic nanoparticles (MNP). These magnetic immunoassays have the advantage that they are insensitive to other biological substances and therefore stable over the long term. They can also be used in optically opaque media (e.g. whole blood) and manipulated using magnetic fields. Magnetic immunoassays are based on the change in the hydrodynamic volume of an MNP as a result of the specific binding of biological targets, such as proteins or antibodies. The change is directly proportional to the Brown time constant, which describes the physical rotation of an MNP in a magnetic field and can be detected.
The aim of the research is to develop a standardised detection method based on the mix and measure principle that is both cost-effective and quick to perform. In addition to the assay design, a compact measuring system is also being developed that can be used at the point-of-need.
