Fluorescent magnetic nanoparticles and process of preparation

• US 9,512,001 B2
• Filed: 12/16/2010
• Issued: 12/06/2016
• Est. Priority Date: 08/08/2003
• Status: Active Grant

• Current Assignee: CapitalBio Corporation, Tsinghua University
• Original Assignee: CapitalBio Corporation, Tsinghua University
• Inventors: Lu, Huachang, Yi, Guangshun, Chen, Depu, Guo, Lianghong, Cheng, Jing
• Primary Examiner(s): Shibuya, Mark
• Assistant Examiner(s): DO, PENSEE T
• Application Number:
  US12/970,688
• Publication Number:
  US 20110177339A1
• Time in Patent Office: 2,182 Days
• Field of Search: 436/526
• US Class Current: 1/1
• 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 33/54326 Magnetic particles
• CPC Class Codes: G01N 33/588 with semiconductor nanocrystal label, e.g. quantum dots
• CPC Class Codes: Y10T 428/2991 Coated

Abstract

This invention provides nanometer-sized fluorescent magnetic particles and processes of making them. The nanoparticle has a core particle comprising a magnetic material and a fluorescent material, and the particle size is less than about 1 micrometer. The nanoparticles can be coated with an inorganic or organic layer and can be surface-modified. The nanoparticles can be used in many biological assays.

Claims

1. A nanoparticle comprising a core particle and an outer shell, wherein the core particle comprises a magnetic particle, a fluorescent particle, and a material that binds the magnetic particle and the fluorescent particle together, wherein the fluorescent particle comprises an up-converting phosphor fluoride, wherein the core particle is coated with the outer shell, and wherein the size of the nanoparticle is less than about 1 micrometer.

2. The nanoparticle of claim 1, wherein the size of the nanoparticle is less than about 300 nanometers.

3. The nanoparticle of claim 1, wherein the size of the nanoparticle is ranging from about 80 nanometers to about 200 nanometers.

4. The nanoparticle of claim 1, wherein the magnetic particle comprises a superparamagnetic, a paramagnetic or a ferromagnetic material.

5. The nanoparticle of claim 1, wherein the magnetic particle comprises a metal oxide.

6. The nanoparticle of claim 5, wherein the metal oxide is selected from the group consisting of oxide of cobalt, nickel, manganese, and iron.

7. The nanoparticle of claim 1, wherein the saturation magnetization of the nanoparticle is between about 5 emu/g and about 60 emu/g.

8. The nanoparticle of claim 1, wherein the fluorescent particle is a fluorescent nanometer-sized particle.

9. The nanoparticle of claim 1, wherein the core particle comprises a magnetic particle covered by a layer of the fluorescent particle.

10. The nanoparticle of claim 1, wherein the core particle comprises a fluorescent particle covered by a layer of the magnetic material.

11. The nanoparticle of claim 1, wherein the core particle comprises fluorescent particles doped with the magnetic material.

12. The nanoparticle of claim 1, wherein the core particle comprises magnetic particles doped with the fluorescent material.

13. The nanoparticle of claim 1, which comprises a bio-molecule.

14. The nanoparticle of claim 13, wherein the bio-molecule is selected from the group consisting of an amino acid, a peptide, a protein, a nucleoside, a nucleotide, an oligonucleotide, a nucleic acid, a vitamin, a monosaccharide, an oligosaccharide, a carbohydrate, a lipid and a complex thereof.

15. The nanoparticle of claim 1, wherein the material that binds the magnetic particle and the fluorescent particle together comprises SiO₂ or a polymeric organic compound.

16. The nanoparticle of claim 1, wherein the outer shell comprises silica or a polymeric organic compound.

17. The nanoparticle of claim 1, wherein the fluorescent particle is a fluorescein-doped silica particle.

18. The nanoparticle of claim 1, wherein the surface of the nanoparticle comprises a functional group.

19. The nanoparticle of claim 18, wherein the functional group is selected from the group consisting of —

COOH, —

CHO, —

NH₂, —

SH, —

S—

S—

, a sulfhydryl group, an epoxy group, and a trimethoxysilyl group.