The invention provides a compound. The compound is shown in a formula (I), wherein R1 and R2 are selected from H or groups shown in a formula (II) independently, and at least one of the R1 and R2 is agroup selected from the formula (II); R3 is selected from groups consisting of H, F, Cl, Br, OH, OCH3, N(CH3)2 or C1-C6 alkyl groups, and R4 is selected from the C1-C6 alkyl groups. Compared with anexisting embedded fluorescent probe, since a fluorescent probe provided by the invention is provided with a large electron conjugated system and a large plane, the fluorescence emission intensity of the molecule of the fluorescent probe can be influenced by the intensity of a charge transfer effect in the molecule of the fluorescent probe, and when the fluorescent probe combines with G-quadruplexRNA specifically, the flexibility of rotary intramolecular double bonds is limited, so that the effect of intramolecular charge transfer is enhanced, and thus the fluorescence intensity is increased;the fluorescent probe provided by the invention has no biological toxicity, no phototoxicity and no fluorescence quenching, meanwhile, the solubility in water and the cellular permeability are greatlyimproved, and the fluorescent probe has a high binding constant in detection and an extremely low limit of detection.