Application of small-molecule fluorescent probe with dual fluorescence emission

The invention belongs to the technical field of molecular detection, and particularly relates to application of a small-molecular fluorescent probe with double fluorescence emission. When the small-molecule fluorescent probe interacts with double-stranded DNA (dsDNA), double fluorescence emission occurs under the excitation condition of an excitation wavelength of 350-550 nm, with the strongest fluorescence emission peaks being 640+/-5 nm and 540+/-5 nm, respectively. Due to the unique molecular structure, the fluorescent probe molecule shows unique double-fluorescence emission phenomenon wheninteracting with the dsDNA, and the phenomenon is utilized to apply the fluorescent probe molecule to the preparation of a specific recognition reagent of the dsDNA, so that a technical problem of acumbersome and complex dsDNA detection process in the prior art is solved. The fluorescent probe has a structure as shown in formula (I): wherein R is: or n is an integer of 1-12.