Interaction of Gold Nanoparticles with Cyanine Dyes in Cholesteric DNA Submicroparticles: Impact of the Way of Their Introduction into the System

The results of two different ways of introducing SYBR Green I (SG) and PicoGreen (PG) cyanine dyes, as well as ultrasmall gold nanoparticles (GNPs) in a cholesteric liquid-crystalline dispersion (CLCD) of DNA, are compared: preliminary incubation with DNA and introduction in a ready-made dispersed system. In the absence of dyes and in the presence of SG, the preliminary incubation of GNPs in a DNA solution leads to an increase in the destruction of its cholesteric phase. At the same time, more efficient quenching of SG fluorescence was observed upon the injection of GNPs in a ready-made dispersed system. For the case of PG, the order of introduction of the components does not affect either the properties of the DNA CLCD or the fluorescence of the dye.