ИСТИНА

Biorecognition elements (antibodies, aptamers, lectins etc.) are key components in most sensor systems. Specific interactions of analytes with biomolecules provide high selectivity of the sensors is provided by specific interactions of analytes with biomolecules, however, they suffer from high cost, special storage conditions and lack of operational stability. Besides, they require catalytically or electrochemically active labels which limit their applicability due to additional analysis steps and impossibility of continuous monitoring. Using synthetic receptors instead of biomolecules improve operational stability oh sensors. For example, boronic acids selectvely binding to 1,2- or 1,3-diols are alternative to lectines that possess high affinity to saccharides. Since the latter is one of major components of cell wall or cell membrane, "synthetic lectines" are able to solve some important medical or biotechnological objectives includind air and product purity. However, existing methods of microorganism detection usually consist of additional pretreatment steps or reqiure expensive eqiupment and reagents. Here we demonstrate reagentless sensor based on boronate-substituted polyaniline that generates electrochemical signal in the course of specific interactions with 1,2- or 1,3-diol moiety. Developed system is applicable for microorganism's detection in water and aerosol. The reported sensor allows discrimination of specific acffinity interactions from non-specific binding. Underlyind mechanism consists in self-doping phenomenon originating upon formation of negatively charged complex between boronate substituent of boronate-substituted polyaniline and diol fragments of saccharides and hydroxyacids [1]. Sensor applicability to microorganisms' detection was proved on the base of impedimetric detection of Penicillium chrysogenum. We have chosen interdigitated microelectrode arrays (IDMEAs) that are among the most sensitive electrode structures used for this aim. Impedance spectra of boronate-substituted polyaniline-modified IDMEAs were recorded in liquid and aerosol. Impedance data in Nyquist plots demonstrate decrease of film resistance (discovered from the diameter of high-frequency semicircle, starting from the bottom left part) as a function of mold concentration. As seen, polyaniline film conductivity increases together with mold concentration. Detection limits are from 600 to 2100 CFU/ml (liquid) and from 200 to 800 CFU/m3 (aerosol). Acknowledgments Financial support through Russian Science Foundation grant #16-13-00010 is greatly acknowledged References [1] E.A. Andreyev, M.A. Komkova, V.N. Nikitina, N.V. Zaryanov, O.G. Voronin, E.E. Karyakina, A.K. Yatsimirsky, A.A. Karyakin. Anal. Chem. 2014, 86, 11690–11695