A new simple electrochemical immunosensor approach for the determination of antibodies to tick-borne encephalitis virus (TBEV) in immunological products was developed and tested. The assay is performed by detecting the silver reduction signal in the bioconjugates with antibodies (Ab@AgNP). Here, signal is read by cathodic linear sweep voltammetry (CLSV) through the detection of silver chloride reduction on a gold–carbon composite electrode (GCCE). Covalent immobilization of the antigen on the electrode surface was performed after thiolation and glutarization of the GCCE. Specific attention has been paid to the selection of conditions for stabilizing both the silver nanoparticles and their Ab@AgNP. A simple flocculation test with NaCl was used to select the concentration of antibodies, and the additional stabilizer bovine serum albumin (BSA) was used for Ab@AgNP preparation. The antibodies to TBEV were quantified in the range from 50 IU·mL⁻¹ to 1600 IU·mL⁻¹, with a detection limit of 50 IU·mL⁻¹. The coefficient of determination (r²) is 0.989. The electrochemical immunosensor was successfully applied to check the quality of immunological products containing IgG antibodies to TBEV. The present work paves the path for a novel method for monitoring TBEV in biological fluids.

Gluconic acid and its derivatives are extensively used in pharmaceutical, food, textile, and pulp and paper branches of industry during production of food additives, cleansers, medicinal drugs, stabilizers, etc. To obtain gluconic acid, the method of conversion of glucose into gluconic acid by molecular oxygen in the presence of solid catalysts is promising. The process of obtaining Pd and bimetallic nanoparticles Pd-Bi, coated on Al₂O₃, has been considered in the work. Samples were prepared by combined and successive impregnation of the Al₂O₃ support using metalloorganic precursors Pd(acac)₂, Bi(ac)₃, and dissolved in an organic solvent (acetic acid), followed by the removal of excess solvent. To achieve the formation of Pd and bimetallic nanoparticles Pd-Bi on the substrate surface, the synthesized samples were subjected to thermal decomposition sequentially in the atmosphere of Ar, O₂, and H₂. The surface of the obtained catalysts was studied by a combination of physicochemical methods of analysis. The catalysts were analyzed in the reaction of liquid phase oxidation of glucose. The best results are achieved in the presence of the catalyst obtained by combined impregnation.

The study is devoted to optimization of synthesis of vanillylmandelic acid as an intermediate product in vanillin production and analytical determination of all components of the reaction mixture. It was noted that variation of synthesis temperature, reaction time and rate of initial reagents affects on the yield of vanillylmandelic acid. Guaiacol disubstituted by two glyoxylic acid molecules is the main impurity in vanillylmandelic acid synthesis what was identified by high resolution HPLC-MS. It is determined that it is optimal to carry out the condensation of guaiacol and glyoxylic acid at the temperature of the reaction mixture no higher than 30 °С and a mole ratio glyoxylic acid: guaiacol not less than 1: 1.5.

The composition of flavonoids in the above-ground part of Serratula species – S. manschurica Kitag., S. gmelinii Tausch., S. cupuliformis Nakai & Kitagawa, introduced in the Siberian Botanical Garden of Tomsk State University, was studied. Comparative HPLC analysis of extracts showed that S. cupuliformis is the most promising species in terms of flavonoid composition and content. The isolation of the sum of flavonoids from the above-ground part of Serratula cupuliformi by selective extraction and subsequent separation on columns allowed us to isolate an individual major flavonoid. Using HPLC-MS methods, it was identified as 5,7,2',4'-tetrahydroxy-3-methoxyflavone; the presence of a number of other flavonoids was established: isosilichristin, resokaempferol, amorphigenin glucoside, etc. An analysis of the literature data showed that 5,7,2',4'-tetrahydroxy-3-methoxyflavone was identified for the first time in the species of the genus Serratula. The results of the analysis of the flavonoid content during the vegetative development of the studied species indicate that the phase of maximum flavonoid accumulation is the periods of active plant growth - the beginning of the vegetation period for S. cupuliformis, flowering for S. manshurica and S. gmelinii. It is noted that during the vegetative development of S. cupuliformis, some flavonoids (5,7,2',4'-tetrahydroxy-3-methoxyflavone) are found in all phases of vegetation, while the presence of others is established in certain periods of development. In all likelihood, such distribution and selective synthesis of individual flavonoids is due to the needs of plants and the participation of phenolic compounds in certain stages of metabolism.