Fluorescent probe with characteristic of charge transfer, and preparation method and application thereof

The invention discloses a fluorescent probe with the characteristic of charge transfer, and a preparation method and an application thereof, belonging to the fields of chemical synthesis, chemical analysis and biological analysis. According to the invention, the structure of the probe comprises the parts of electron-donating triphenylamine and electron-deficient quinoline salt, so the probe has the property of intramolecular charge transfer. The fluorescent probe has the following advantages: the synthetic route has high operability; the purification method is simple; the preparation cost is low; and good market competitiveness is obtained. The fluorescent probe has stable structure and low fluorescence background, wherein the fluorescence enhancement exceeds one hundred times after specific binding of the fluorescent probe with a G-quadruplex. Through fluorescence spectrum, a secondary structure of a DNA sample can be rapidly detected, and the disadvantages like high price, long cycle and complicated technical operation in the prior art are overcome.