Nanocrystals

• US 7,198,847 B2
• Filed: 09/29/2004
• Issued: 04/03/2007
• Est. Priority Date: 09/17/2001
• Status: Active Grant

• Current Assignee: Life Technologies Corporation (Thermo Fisher Scientific Incorporated)
• Original Assignee: Invitrogen Corp. (Thermo Fisher Scientific Incorporated)
• Inventors: Naasani, Imad
• Primary Examiner(s): Kiliman; Leszek
• Application Number:
  US10/952,701
• Publication Number:
  US 20050112376A1
• Time in Patent Office: 916 Days
• Field of Search: 428/403, 428/407, 428/630, 252/301.4 R, 252/301.4 S, 252/301.6 R, 252/301.6 S
• US Class Current: 428/403
• 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: G01N 33/588 with semiconductor nanocrystal label, e.g. quantum dots
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/2993 Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]
• CPC Class Codes: Y10T 428/2998 including synthetic resin or polymer
• CPC Class Codes: Y10T 428/31721 Of polyimide

Abstract

Provided herein are compositions of functionalized, fluorescent nanocrystals comprising fluorescent nanocrystals coated with an imidazole-containing compound; compositions of functionalized, fluorescent nanocrystals comprising fluorescent nanocrystals coated with an imidazole-containing compound and cross-linked with a phosphine cross-linking compound; compositions of functionalized fluorescent nanocrystals operably bound to molecular probe; a process of making functionalized, fluorescent nanocrystals; and a process of using functionalized, fluorescent nanocrystals in a detection system.

Claims

1. A functionalized fluorescent nanocrystal comprised of:

a fluorescent nanocrystal; and

an imidazole-containing capping layer wherein the capping layer further comprises a phosphine cross-linking compound.

2. The functionalized fluorescent nanocrystal of claim 1, wherein the fluorescent nanocrystal comprises a core semiconductor nanocrystal, a core/shell semiconductor nanocrystal, a doped metal oxide nanocrystal, or a mixture thereof.

3. The functionalized fluorescent nanocrystal of claim 2, wherein the fluorescent nanocrystal is a core nanocrystal co-precipitated with a metal salt shell.

4. The functionalized fluorescent nanocrystal of claim 3, wherein the metal salt shell comprises a semiconductor material with a higher band gap energy than the core nanocrystal.

5. The functionalized fluorescent nanocrystal of claim 3, wherein the core nanocrystal comprises a Group II-VI semiconductor and the metal salt shell comprises a Group II-VI semiconductor.

6. The functionalized fluorescent nanocrystal of claim 3, wherein the core nanocrystal comprises a Group II-VI semiconductor and the metal salt shell comprises a compound comprising sulfur and a metal selected from the group consisting of zinc, copper, iron, nickel, cadmium, cobalt, and mixtures thereof.

7. The functionalized fluorescent nanocrystal of claim 3, wherein the core nanocrystal comprises cadmium selenide and the metal salt shell comprises zinc sulfide.

8. The functionalized fluorescent nanocrystal of claim 3, wherein the imidazole-containing capping layer comprises a functional group comprising an ion operably bound to the metal salt shell.

9. The functionalized fluorescent nanocrystal of claim 3, wherein the imidazole-containing capping layer comprises a nitrogen operably bound to the metal salt shell.

10. The functionalized fluorescent nanocrystal of claim 3, wherein the capping layer is uniformly deposited over an outer surface of the fluorescent nanocrystal.

11. The functionalized fluorescent nanocrystal of claim 3, wherein the imidazole-containing capping layer passivates the fluorescent nanocrystal.

12. The functionalized fluorescent nanocrystal of claim 3, wherein the fluorescence intensity of the functionalized fluorescent nanocrystal is greater than the fluorescence intensity of a non-functionalized fluorescent nanocrystal.

13. The functionalized fluorescent nanocrystal of claim 3, wherein the fluorescence intensity of the functionalized fluorescent nanocrystal is enhanced up to about 1100 fold when compared to a non-functionalized fluorescent nanocrystal.

14. The functionalized fluorescent nanocrystal of claim 3, wherein the fluorescence intensity of the functionalized fluorescent nanocrystal is enhanced about 30 to about 300 fold when compared to a non-functionalized fluorescent nanocrystal.

15. The functionalized fluorescent nanocrystal of claim 3, wherein the fluorescence intensity of the functionalized fluorescent nanocrystal is enhanced about 10 to about 100 fold when compared to a non-functionalized fluorescent nanocrystal.

16. The functionalized fluorescent nanocrystal of claim 3, wherein the imidazole-containing capping layer is cross-linked.

17. The functionalized fluorescent nanocrystal of claim 3, wherein the functionalized fluorescent nanocrystal is soluble in aqueous solutions.

18. The functionalized fluorescent nanocrystal of claim 3, wherein the functionalized fluorescent nanocrystal is stable in aqueous solutions at about pH 6 to about pH 10.5.

19. The functionalized fluorescent nanocrystal of claim 3, wherein the functionalized fluorescent nanocrystal is stable in aqueous solutions at about pH 7 to about pH 9.

20. The functionalized fluorescent nanocrystal of claim 3, wherein the functionalized fluorescent nanocrystal is stable in aqueous solutions at about pH 8 to about pH 10.

21. The functionalized fluorescent nanocrystal of claim 3, wherein the functionalized fluorescent nanocrystal is operably bound to a molecular probe.

22. A method for detecting a target molecule, the method comprising:

forming a complex by operably bonding a functionalized fluorescent nanocrystal to a target molecule, wherein the functionalized fluorescent nanocrystal comprises an imidazole-containing capping layer wherein the capping layer further comprises a phosphine cross-linking compound;

exciting the complex; and

detecting light emitted from the complex.