ИСТИНА

The problem of aspergillosis is aggravated by the increasing resistance of pathogens to antifungal drugs, as well as the appearance of multi-resistant strains. Early and accurate diagnosis of invasive aspergillosis is a serious problem because there is a wide range of nonspecific clinical symptoms. One of the promising diagnostic methods is the development of biosensors. Electrolyte-gated organic field-effect transistors (EGOFET) are a promising platform for ultra-sensitive, fast and reliable detection of biological molecules. The ability of lable-free response using a simple electronic reading circuit is one of the main advantages of such devices compared to other identification technologies. With the help of EGOFET-biosensors, very low concentrations of analytes can be detected, which may correspond to diseases in the early stages. Aspergillus cell wall components, such as oligosaccharides and glycoproteins, can be the basis of various biosensor platforms for detecting infection by Aspergillus species. Oligosaccharides can be integrated into the EGOFET due to a biotin-streptavidin platform located on the surface of the organic semiconductor layer of the device. And potential targets for analysis may be monoclonal antibodies that exhibit a specific interaction with oligosaccharides. Nowadays, the standard for determining mold fungi is a test based on Limulus amoebocyte lysate (LAL), but this method has a serious disadvantage – a large number of false positive results. This work is aimed at studying the response of the bioreceptor layer in the EGOFETbiosensor containing biotinylated oligosaccharides related to galactomannan, β-(1→3)-Dglucan, β-(1→6)-D-glucan, which are part of the cell wall of the fungus Aspergillus, to monoclonal antibodies 7B8, 5H5, 1D2, specific to oligosaccharides, respectively, as a platform for rapid diagnosis of fungal disease. A specific response of the EGOFET-biosensor to oligosaccharides was demonstrated, as well as various control experiments were conducted. Based on the data of electrical characteristics and fluorescence microscopy, the selectivity of the device is shown. The concentrations of monoclonal antibodies detected using a biosensor are comparable to the results obtained by enzyme immunoassay based on antibodies and can compete with other test with advantage of rapidness of EGOFET sensors response. This work was carried out with the support of the Russian Foundation for Basic Research № FFSM-2022-0001