Multifunctional nanostructures, methods of synthesizing thereof, and methods of use thereof

1. A nanostructure, comprising:

a. a quantum dot (QD);

b. a hydrophobic protection structure including at least one compound selected from a capping ligand, an amphiphilic copolymer, and combinations thereof, wherein the hydrophobic protection structure encapsulates the QD; and

c. at least one histidine-tagged peptide or at least one histidine-tagged protein, conjugated to the hydrophobic protection structure, wherein the at least one histidine-tagged peptide or protein has at least one binding site.

2. The nanostructure of claim 1 , wherein the amphiphilic copolymer is selected from amphiphilic block copolymers, amphiphilic random copolymers, amphiphilic alternating copolymers, amphiphilic periodic copolymers, and combinations thereof.

3. The nanostructure of claim 1 , wherein the amphiphilic copolymer is a block copolymer selected from a diblock copolymer, a triblock copolymer, and combinations thereof.

4. The nanostructure of claim 3 , wherein the amphiphilic block copolymer includes an ABC triblock structure having grafted 8-carbon alkyl side chains.

5. The nanostructure of claim 4 , wherein the ABC triblock structure includes a poly-butylacrylate segment, a poly-ethylacrylate segment, and a poly-methacrylic acid segment.

6. The nanostructure of claim 1 , wherein the amphiphilic copolymer has a molecular weight of about 50,000 Da to 200,000 Da, preferably about 100,000 Da.

7. The nanostructure of claim 1 , wherein the quantum dot comprises a core and a cap.

8. The nanostructure of claim 7 , wherein the core of the quantum dot is selected from the group consisting of IIA-VIA semiconductors, IIIA-VA semiconductors, IVA-IVA semiconductors, and IVA-VIA semiconductors.

9. The nanostructure of claim 7 , wherein the core of the quantum dot is selected from the group consisting of IIA-VIA semiconductors.

10. The nanostructure of claim 7 , wherein the core of the quantum dot is CdSe.

11. The nanostructure of claim 7 , wherein the cap is selected from the group consisting of IIA-VIA semiconductors of high band gap.

12. The nanostructure of claim 7 , wherein the cap is selected from ZnS.

13. The nanostructure of claim 1 , further comprising a bio-compatibility compound substantially disposed on the hydrophobic protection structure.

14. The nanostructure of claim 13 , wherein the bio-compatibility compound is a polyethylene glycol molecule having a molecular weight of about 500 Da to 50,000 Da.

15. The nanostructure of claim 1 , further comprising a probe disposed on the hydrophobic protection structure, wherein the probe is selected from an antibody, a polypeptide, a polynucleotide, a drug molecule, an inhibitor compound, and combinations thereof.

16. The nanostructure of claim 1 , wherein the capping ligand includes tri-octylphosphine oxide.

17. The nanostructure of claim 1 , further comprising a chelating compound for conjugating the at least one histidine-tagged peptide or protein to the hydrophobic protection structure by forming two or more coordinating bonding with the at least one histidine-tagged peptide or protein and the hydrophobic protection structure, respectively.

18. The nanostructure of claim 17 , wherein the chelating compound comprises nickel-nitrilotriacetic acid (Ni-NTA).

19. The nanostructure of claim 1 , wherein the at least one histidine-tagged peptide or protein comprises a histidine-tagged amino-terminal fragment (ATF) of urokinase plasminogen activator (uPA).

20. The nanostructure of claim 1 , wherein the binding site of the at least one histidine-tagged peptide or protein can be at the C-terminal, N-terminal or inside of the peptide or protein between two functional domains on the peptide or protein.