Photochemical evaluation of dual fluorescence of a novel DNA groove binder

: We synthesized the fluorophore-tethered oligopeptide showing a dual fluorescence in water, and the ratiometric fluorescence change of the modified oligopeptide was induced by the binding to DNA. The equilibrium of the modified oligopeptide between two excited states, a locally excited (LE) state and an intramolecular charge transfer (ICT) state, was controlled depending to DNA structures.