Functionalized nanoparticles and methods of use

• US 20040067503A1
• Filed: 04/22/2003
• Published: 04/08/2004
• Est. Priority Date: 04/22/2002
• Status: Active Grant

• Current Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Inventors: Tan, Weihong, Shouguang, Jin, Zhao, Xiaojun, Hilliard, Lisa Renee, Dytioco, Rovelyn Tapec, Drake, Timothy James
• Granted Patent: US 7,524,630 B2
• Time in Patent Office: Days
• US Class Current: 435/6
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: C12Q 1/6816 characterised by the detection means C12Q1/6804 takes precedence
• CPC Class Codes: C12Q 2563/155 Particles of a defined size, e.g. nanoparticles
• CPC Class Codes: G01N 33/54346 Nanoparticles
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: G01N 33/552 Glass or silica
• CPC Class Codes: G01N 33/588 with semiconductor nanocrystal label, e.g. quantum dots

Abstract

Silica-coated nanoparticles functionalized with biologically active molecules such as antibodies and nucleotides are used to label cells, to detect and isolate nucleic acid molecules having specific nucleotide sequences, and to separate a mixture of different nucleic acid molecules.

Claims

1. A method of directing a nanoparticle to a target molecule, the method comprising the steps of:

(a) providing a nanoparticle comprising a silica surface, the silica surface being conjugated with at least one functional group capable of specifically binding the target molecule;

(b) mixing together the nanoparticle and the target molecule under conditions that allow the at least one functional group to bind the target molecule.

2. The method of claim 1, wherein the nanoparticle further comprises a core enveloped by the silica surface.

3. The method of claim 2, wherein the core comprises a metal.

4. The method of claim 3, wherein the metal is magnetic.

5. The method of claim 2, wherein the core comprises a dye.

6. The method of claim 5, wherein the dye is an organic dye.

7. The method of claim 5, wherein the dye is an inorganic dye.

8. The method of claim 5, wherein the dye is selected from the group consisting of:

Ru II/2,2′

-dipyridyl, Eu³⁺/2,2′

-dipyridyl, rhodamine 6G, tetramethyl rhodamine, and fluorescein.

9. The method of claim 1, wherein the functional group is a protein.

10. The method of claim 9, wherein the protein is an antibody.

11. The method of claim 9, wherein the protein is an enzyme.

12. The method of claim 9, wherein the protein is avidin.

13. The method of claim 9, wherein the protein is biotin.

14. The method of claim 1, wherein the functional group is a nucleic acid.

15. The method of claim 14, wherein the nucleic acid is a DNA.

16. The method of claim 14, wherein the nucleic acid is in the form of a molecular beacon.

17. The method of claim 16, wherein the molecular beacon is conjugated with a fluorophore.

18. The method of claim 17, wherein the molecular beacon is further conjugated with a quencher of the fluorophore.

19. The method of claim 1, wherein the functional group is conjugated to the silica surface via a biotin-avidin linkage.

20. The method of claim 1, wherein the target molecule is within a cell.

21. The method of claim 20, wherein the target molecule is on the cell'"'"'s surface.

22. The method of claim 20, wherein the target molecule is located within the cell'"'"'s interior.

23. The method of claim 20, wherein the cell is a eukaryotic cell.

24. The method of claim 23, wherein the eukaryotic cell is a mammalian cell.

25. The method of claim 24, wherein the mammalian cell is a cancer cell.

26. The method of claim 20, wherein the cell is a prokaryotic cell.

27. The method of claim 26, wherein the prokaryotic cell is a bacterium.

28. The method of claim 1, wherein the target molecule is contained in a liquid.

29. The method of claim 1, further comprising the step (c) of detecting binding of the nanoparticle to the target molecule.

30. The method of claim 29, wherein binding of the nanoparticle to the target molecule is detected by observing a change in a property of the nanoparticle.

31. The method of claim 30, where the property is light emission.

32. The method of claim 1, wherein the target molecule is contained within a mixture, the method further comprising the step (c) of isolating from the mixture a complex comprising the nanoparticle bound to the target molecule.

33. The method of claim 32, further comprising the step (d) of separating the target molecule from complex.