Fluorescent dye and preparation method and use thereof

A fluorescent dye, having a structure represented by formula (I)

• wherein,
• D- is —OH or N(X1)(X2)—;
• X1, and X2 are each independently selected from the group consisting of hydrogen, an alkyl group and a first modified alkyl group;
• the first modified alkyl group is a group obtained by replacing any carbon atom or any carbon atom with hydrogens thereon of the alkyl group with at least one group selected from the group consisting of a halogen atom, —O—, —OH, —CO—, —CN, —SO2—, —(S═O)—, a primary amino group, a secondary amino group, and a tertiary amino group, the first modified alkyl group has 1 to 11 carbon atoms, X1 and X2 are optionally linked to each other to form a saturated or unsaturated alicyclic heterocyclic ring;
• the alicyclic heterocyclic ring is selected from the group consisting of azetidine, pyrrolidine, piperidine, and morpholine;
• the ring B is selected from at least one consisting of an aromatic ring and an aromatic heterocyclic ring;
• in the structure of the following formula (I-2) formed by condensing the ring B with a thiophene ring, each hydrogen atom contained therein is optionally replaced independently with a substituent selected from the group consisting of an alkyl group and a methoxy group
• wherein R1 is hydrogen;
• R2 is selected from the group consisting of cyano, carboxyl, a keto group, an ester group, an amide group, an aryl group, a heteroaryl group, and a second modified alkyl group;
• the second modified alkyl group is a group obtained by replacing any carbon atom or any carbon atom with hydrogens thereon of the alkyl group with at least one group selected from the group consisting of —O—, —OH, —CO—, a primary amino group, a secondary amino group, a tertiary amino group, the second modified alkyl group has 1 to 4 carbon atoms;
• and
• R3 is a cyano group;
• or
• the structural moiety of the following formula (I-3) in the formula (I):
• forms a cyclic structure of the following formulae (I-3-a) or (I-3-b):
• wherein, Ra and Rb are selected independently from the group consisting of hydrogen, and an alkyl group;
• Rc is hydrogen;
• R4 is selected independently from the group consisting of hydrogen, an alkyl group, and an aryl group;
• Y1 is selected from the groups consisting of —O—, —S—, —(S═O)—, and —(NRi)—, wherein Ri is selected from the group consisting of hydrogen and an alkyl group;
• Y2 is selected from the group consisting of ═O and ═S;
• and
• Y3 is selected from the group consisting of ═O and ═S;
• wherein,
• the alkyl group is a saturated aliphatic linear or branched alkyl group having 1 to 10 carbon atoms;
• the aryl group is a five to ten-membered monocyclic or condensed bicyclic ring;
• the heteroaryl or the aromatic heterocyclic ring is a five to ten-membered monocyclic or condensed bicyclic ring with at least one heteroatom selected from the group consisting of N, O and S on the ring;
• and
• the halogen atom is each independently selected from the group consisting of F, Cl, Br, and I.