Energy transfer dyes with enhanced fluorescence
View Patent ↗Novel linkers for linking a donor dye to an acceptor dye in an energy transfer fluorescent dye are provided. These linkers faciliate the efficient transfer of energy between a donor and acceptor dye in an energy transfer dye. One of these linkers for linking a donor dye to an acceptor dye in an energy transfer fluorescent dye has the general structure R 21 Z 1 C(O)R 22 R 28 where R 21 is a C 1-5 alkyl attached to the donor dye, C(O) is a carbonyl group, Z 1 is either NH, sulfur or oxygen, R 22 is a substituent which includes an alkene, diene, alkyne, a five and six membered ring having at least one unsaturated bond or a fused ring structure which is attached to the carbonyl carbon, and R 28 includes a functional group which attaches the linker to the acceptor dye.
1. An energy transfer dye comprising:
a xanthene donor dye capable of absorbing light at a first wavelength and emitting excitation energy in response thereto;
a 4,7-dichlororhodamine acceptor dye capable of absorbing the excitation energy emitted by the donor dye and fluorescing at a second wavelength in response thereto; and
a non-nucleosidic linker linking the 5- or 6-ring position of the donor dye to the 5- or 6-ring position of the acceptor dye.
2. The energy transfer dye of claim 1 in which the donor dye is a fluorescein dye.
3. The energy transfer dye of claim 1 in which the linker has a backbone that is less than 9 atoms in length.
4. The energy transfer dye of claim 1 in which the linker comprises a functional group selected from an alkene, a diene, an alkyne, a five membered ring having at least one unsaturated bond, a six membered ring having at least one unsaturated bond and a fused ring structure.
5. The energy transfer dye of claim 1 which further comprises a linking group suitable for attaching the energy transfer dye to another substance.
6. The energy transfer dye of claim 5 in which the linking group is attached to the 4′-position of the 4,7-dichlororhodamine acceptor dye.
7. The energy transfer dye of claim 1 which comprises the structure:
wherein
R 1 , R 2 , R 3 and R 4 are each, independently of one another, selected from hydrogen and alkyl, or alternatively R 1 and R 5 , R 2 and R 6 , R 3 and R 8 and/or R 4 and R 9 may be taken together with the atoms to which they are bonded to form a 5, 6 or 7-membered ring;
R 5 , R 6 , R 7 , R 9 and R 10 are each, independently of one another, selected from hydrogen, fluorine, chlorine, bromine, iodine, carboxyl, alkyl, alkene, alkyne, sulfonate, sulfone, amino, ammonium, amido, nitric, alkoxy, phenyl and substituted phenyl, or alternatively, R 6 and R 7 and/or R 9 and R 10 may be taken together with the atoms to which they are bonded to form a benzo group;
R 8 is selected from hydrogen, fluorine, chlorine, bromine, iodine, carboxyl, alkyl, alkene, alkyne, sulfonate, sulfone, amino, ammonium, amido, nitrile, alkoxy, phenyl, substituted phenyl and linking group;
X 1 and X 3 are each, independently of one another, selected from hydrogen, fluorine, chlorine, bromine, iodine, carboxyl, alkyl, alkene, alkyne, sulfonate, sulfone, amino, ammonium, amido, nitrile and alkoxy;
L is the linker linking the donor and acceptor dyes;
R 11 , R 12 , R 13 , R 15 and R 16 are each, independently of one another, selected from hydrogen, fluorine, chlorine, bromine, iodine, carboxyl, alkyl, alkene, alkyne, sulfonate, sulfone, amino, ammonium, amido, nitrile, alkoxy, phenyl and substituted phenyl, or alternatively, R 12 and R 13 and/or R 15 and R 16 may be taken together with the atoms to which they are bonded to form a benzo group;
R 14 is selected from hydrogen, fluorine, chlorine, bromine, iodine, carboxyl, alkyl, alkene, alkyne, sulfonate, sulfone, amino, ammonium, amido, nitrile, alkoxy, phenyl, substituted phenyl and linking group; and
X 11 , X 12 , X 13 and X 15 are each, independently of one another, selected from hydrogen, fluorine, chlorine, bromine, iodine, carboxyl, alkyl, alkene, alkyne, sulfonate, sulfone, amino, ammonium, amido, nitrile and alkoxy.