Researchers from the General Physics Institute of the Russian Academy of Sciences (GPI RAS) and Moscow Institute of Physics and Technology (MIPT) have developed a new biosensor test system based on magnetic nanoparticles. It is designed to provide highly accurate measurements of the concentration of protein molecules (e.g. markers, which indicate the onset or development of a disease) in various samples, including opaque solutions or strongly coloured liquids.
At molecular level, the magnetic nanoparticles "link" with antibodies to the required protein and then they are placed on a porous plate close to the intended point of contact with the test solution. The liquid, which spreads along the plate due to capillary action, captures the magnetic particles. It then meets two lines - the test line and the control line. The test line contains antibodies that capture the protein in question and also the magnetic markers that became attached to molecules of the protein due to the fact that the nanoparticles are also "linked" to the antibodies. The control line only captures the antibodies with magnetic markers, and it will be activated in any case, if the test strip is usable. The control line serves as an indicator as to whether the test is suitable for use, the protein antibodies in it have not been destroyed due to improper storage, and the test liquid has been applied correctly.
The combination of reliability, accessibility, and high accuracy and sensitivity of the new method means that it is likely to make a rapid transition from a laboratory prototype to mass production.
Scientists have put a high precision blood assay into a simple test strip