Coated water-soluble nanoparticles comprising semiconductor core and silica coating

• US 7,405,002 B2
• Filed: 08/04/2004
• Issued: 07/29/2008
• Est. Priority Date: 08/04/2004
• Status: Expired due to Fees

• Current Assignee: Agency For Science Technology and Research
• Original Assignee: Agency For Science Technology and Research
• Inventors: Ying, Jackie Y., Tan, Timothy T., Selvan, Subramanian T.
• Primary Examiner(s): LE, HOA T
• Application Number:
  US10/911,402
• Publication Number:
  US 20060029802A1
• Time in Patent Office: 1,455 Days
• Field of Search: 428/403, 428/404, 428/407, 977/773, 977/777
• US Class Current: 428/404
• CPC Class Codes: C30B 29/60 characterised by shape
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/777 Metallic powder or flake
• 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

Abstract

Nanoparticles and methods of making nanoparticles are provided. The nanoparticles may include semiconductor nanocrystals. A shell may encapsulate a nanoparticle core, and the shell may include non-organic material and may be silica. The shell may also include additional species such as PEG. In some embodiments, a passivation layer is in contact with the core.

Claims

1. A coated nanoparticle comprising:

a core comprising a semiconductor material;

a non-semi-conductor passivation layer, wherein the passivation layer comprises aminopropyl trimethoxysilane; and

a non-organic shell comprising silica and polyethylene glycol or a derivative thereof encapsulating at least partially the core and the passivation layer.

2. The coated nanoparticle of claim 1, wherein the nanoparticle is water soluble.

3. The nanoparticle of claim 2 wherein the non-organic shell is not chemically bound to the core.

4. The nanoparticle of claim 1 wherein the polyethylene glycol has a molecular weight of about 5,000 to 10,000.

5. The nanoparticle of claim 1, wherein the nanoparticle is soluble in an aqueous solution having a pH of less than about 8.0.

6. The nanoparticle of claim 1, wherein the nanoparticle is soluble in an aqueous solution having a pH of less than or equal to 7.

7. The nanoparticle of claim 1 having a mean diameter of less than 50 nm.

8. The nanoparticle of claim 1 having a mean diameter of less than or equal to 25 nm.

9. The nanoparticle of claim 1 having an emission at 550-600 nm.

10. The nanoparticle of claim 1 having a quantum yield of about 10-20% in an aqueous medium.

11. The nanoparticle of claim 1, wherein the core comprises a cadmium chalcogenide.

12. The nanoparticle of claim 1, wherein the core comprises CdSe.

13. The nanoparticle of claim 1, wherein the core comprises CdSe/ZnS.