Cationic styryl dyes for DNA labelling and selectivity toward cancer cells and Gram-negative bacteria

Fluorescence-based methods are important tools for the analysis of nucleic acids in vitro and in cells. In this study, two cationic cyanine–styryl derivatives were produced using a two-step synthesis. Their optical properties were evaluated in different solvents, and frontier molecular orbital theory was utilized to interpret the findings. The DNA binding of these molecules was investigated to show fluorescence intensification. The molecular docking of both dyes in DNA illustrated the relevance of the electrostatic interaction between the quaternary ammonium of both dyes and the phosphate of the DNA backbone. Last but not least, applications of the synthesized styryl dyes were demonstrated to be selective towards cancer cells and particular kinds of bacteria.