Fluorescent methods and materials for directed biomarker signal amplification
Methods and compositions are provided that include a multichromophore and/or multichromophore complex for identifying a target biomolecule. A sensor biomolecule, for example, an antibody can be covalently linked to the multichromophore. Additionally, a signaling chromophore can be covalently linked to the multichromophore. The arrangement is such that the signaling chromophore is capable of receiving energy from the multichromophore upon excitation of the multichromophore. Since the sensor biomolecule is capable of interacting with the target biomolecule, the multichromophore and/or multichromophore complex can provide enhanced detection signals for a target biomolecule.
1. A water soluble multichromophore that is a conjugated polymer having a backbone of π-conjugated repeat units, the multichromophore comprising the structure:
wherein:
CP 1 has the structure:
wherein each R 1 is independently a water-soluble group comprising one or more groups selected from ethylene glycol oligomer, ethylene glycol polymer, ω-ammonium alkoxy salt and w-sulfonate alkoxy salt;
CP 2 is an aromatic repeat unit that is different from CP 1 ;
CP 3 is present and is an aromatic repeat unit comprising a bioconjugation functional group that is capable of covalently linking to a biomolecule or dye and that does not comprise a biotin group;
m and n are independently 0 to 10,000 wherein m+n>1;
b is 0 to 250 and a and c are independently 1 to 250, wherein a+b+c>1; and *=site for covalent attachment to unsaturated backbone of the multichromophore.
2. The multichromophore according to claim 1 , wherein CP 2 and CP 3 are each independently a carbocyclic or heterocyclic aryl group selected from benzene, naphthalene, anthracene, fluorene, thiophene, furan, pyridine, oxadiazole and substituted versions thereof.
3. The multichromophore according to claim 2 , wherein CP 2 is present and is a substituted fluorene.
4. The multichromophore according to claim 3 , wherein CP 2 has the structure:
wherein each R 1 is independently a water-soluble group comprising one or more groups selected from ethylene glycol oligomer, ethylene glycol polymer, ω-ammonium alkoxy salt and ω-sulfonate alkoxy salt.
5. The multichromophore according to claim 2 , wherein CP 3 is present and is a fluorene substituted with a linker to a bioconjugation functional group capable of covalently linking to a biomolecule or dye.
6. The multichromophore according to claim 2 , wherein CP 3 is present and is a benzene substituted with a linker to a bioconjugation functional group capable of covalently linking to a biomolecule or dye.
7. The multichromophore according to claim 5 , wherein the bioconjugation functional group is selected from maleimide, thiol, succimidyl ester, amine, azide and carboxy/EDC (1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride).
8. The multichromophore according to claim 1 , wherein the multichromophore is further coupled to a signaling chromophore.
9. The multichromophore according to claim 1 , wherein the multichromophore is substituted with a plurality of charge neutral water-soluble groups.
10. The multichromophore according to claim 9 , wherein CP 1 and CP 2 are each independently substituted with one or more water-soluble groups.
11. The multichromophore according to claim 10 , wherein the water-soluble groups comprise one or more groups selected from ethylene glycol oligomer, ethylene glycol polymer, w-ammonium alkoxy salt and w-sulfonate alkoxy salt.
12. A multichromophore-biomolecule conjugate comprising:
a sensor biomolecule covalently linked to a light harvesting multichromophore via a bioconjugation site;
wherein the light harvesting multichromophore is a conjugated polymer having a backbone of π-conjugated repeat units and comprises the structure:
wherein:
CP 1 has the structure:
wherein each R 1 is independently a water-soluble group comprising one or more groups selected from ethylene glycol oligomer, ethylene glycol polymer, w-ammonium alkoxy salt and ω-sulfonate alkoxy salt;
CP 2 is an aromatic repeat unit that is different from CP 1 ;
CP 3 is present and is an aromatic repeat unit comprising the bioconjugation site having a bioconjugation functional group that is capable of covalently linking to a biomolecule or dye and that does not comprise a biotin group;
m and n are independently 0 to 10,000 wherein m+n>1; and
b is 0 to 250 and a and c are independently 1 to 250, wherein a+b+c>1.
13. The multichromophore-biomolecule conjugate according to claim 12 , wherein the sensor biomolecule is a protein, an antibody, a nucleic acid, an affinity ligand, a sugar, a lipid or a peptide.
14. The multichromophore-biomolecule conjugate according to claim 13 , wherein the sensor biomolecule is a protein, an antibody or a nucleic acid.
15. The multichromophore-biomolecule conjugate according to claim 14 , wherein the sensor biomolecule is an antibody.
16. The multichromophore-biomolecule conjugate according to claim 12 , wherein the bioconjugation functional group comprises a linking chemistry selected from maleimide, thiol, succimidylester (NHS ester), amine, azide chemistry, carboxy/EDC (1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride, sulfo-SMCC (sulfosuccinimidyl 4-[N-maleimidomethyl]cyclohexane-1-carboxylate), and amine/BMPH (N-[β-Maleimidopropionic acid]hydrazide•TFA).
17. The multichromophore-biomolecule conjugate according to claim 12 , wherein the light harvesting multichromophore further comprises the structure:
wherein:
L is a linker to a bioconjugation site A covalently linked to the sensor biomolecule; and
*=site for covalent attachment to unsaturated backbone of the multichromophore.
18. The multichromophore-biomolecule conjugate according to claim 12 , wherein CP 3 is covalently linked to a signaling chromophore via the bioconjugation functional group, wherein the signaling chromophore is in energy receiving proximity to the light harvesting multichromophore.