STUDY OF THE INTERACTION OF FLUORESCENT 4'-DODECYLCARBOXY-3-HYDROXYFLAVONE PROBE WITH POLYVINYLPYRROLIDONE

The study examined the interaction of a new ESIPT fluorescent probe, which is based on 4`-dodecyl¬carboxy-substituted 3-hydroxyflavone, with polyvinylpyrrolidone (PVP) at varying polymer concentrations. Through fluorimetric titration, it was determined that the probe's affinity to the polymer relies on the concentration and morphology of PVP in the solution. At low polymer concentrations, a slight increase in fluorescence intensity and a slight hypsochromic shift were observed, indicating a weak probe-polymer interaction. A significant amplification of the probe signal was noticed in high concentration PVP solutions, suggesting the probe's penetration into the hydrophobic environment of the polymer matrix. It was observed that at high concentrations, PVP forms a dense spatial structure, increasing the probe's affinity to the polymer. Molecular docking calculations were utilized to investigate the molecular aspects of the probe-polymer interaction. The binding interactions of the probe ФЛ-С11СООН with PVP macromolecules of different sizes and spatial structures were studied. It was found that the spatial structure of the polymer plays a crucial role in the probe binding. The molecular docking calculations indicated that the probe exhibited weak binding (-4.5 kcal/mol) to an unfolded conformation of PVP100. Conversely, certain hydrophobic sites in a compact, globular matrix of PVP1440 were able to accommodate the probe ФЛ-С11СООН with a high binding affinity of -7.3 kcal/mol. The long-alkyl chain of the probe anchor within at PVP matrix. In summary, it was demonstrated that long-chain fatty acid-functionalized 3-hydroxyflavone derivatives have great potential as environment-sensitive fluorescent probes for studying the microscopic structure and morphology of synthetic polymers, macromolecules, and organized solutions.