Guralchuk G. Effect of formation conditions on optical properties of J-aggregates of polymethine dyes PIC and Cyan-ВTh.

Research objects: J-aggregates of polymethine dyes PIC and Cyan-ВTh. The aim: to establish the influence of preparation conditions on microstructure and spectral-luminescent properties of PIC and Cyan-ВTh J-aggregates in water solutions. Research methods: optical and laser time-correlated photon counting spectroscopy, luminescent microscopy and microspectroscopy. Results, novelty: transformation in time of PIC J-aggregate structure have been found in water-electrolyte (NaCl) solutions. In such solutions the formation of rod-like luminescent crystallites has been observed. It has been shown that the rod-like crystallites are effective light waveguides. The addition of surfactant CPB in a binary solution at the concentration higher than the critical micelle concentration is found to cause the formation of "J-aggregate-surfactant" complexes and significant increases J-aggregate quantum yield. The specificity of Cyan-ВTh aggregation in solutions with DNA and RNA has been revealed that allows J-aggregates Cyan-ВTh to be considered as luminescent probes for nucleic acids (NA) detection. The fields of implementation: development of nanoclusters with controlled optical properties, creation of novel luminescent probes for molecular biology and medicine.