"Turn on" fluorescence response of monomethine cyanines caused by noncovalent binding to ct-DNA. (October 2017) - Levitz, Andrew
Abstract: Monomethine cyanines have been extensively studied for their use as probes for nucleic acids among other biological systems. Four monomethine cyanine dyes were synthesized with various heterocyclic moieties including quinoline, benzoxazole, benzothiazole, and 3, 3-dimethylindolenine adjoining benz[ c, d ]indol-1-ium, which was found to directly influence their optical and energy profiles. The dyes were characterized by 1 H and 13 C NMR and HRMS. In this study the twisted conformation unique to monomethine cyanines was exploited in DNA binding studies where the benzoxazole containing sensor displayed up to 700-fold increase in fluorescence when bound to the DNA compared to the unbound form. Highlights: A series of monomethine cyanines were synthesized in good yield with red-shifted absorbance properties. Computational methods were shown to be useful as a predictive tool for determining their optical properties. The dyes displayed "turn-on" fluorescence when bound to ct-DNA. One of these dyes, OX, displayed a 700-fold increase in fluorescence when bound to 20 μM ct-DNA.