Multifunctional nanocrystals

• US 20060118757A1
• Filed: 12/03/2004
• Published: 06/08/2006
• Est. Priority Date: 12/03/2004
• Status: Active Grant

• Current Assignee: Los Alamos National Security LLC (Government of the United States of America)
• Original Assignee: Los Alamos National Security LLC (Government of the United States of America)
• Inventors: Kim, Hyungrak, Klimov, Victor I., Hollingsworth, Jennifer A., Crooker, Scott A.
• Granted Patent: US 7,261,940 B2
• Time in Patent Office: Days
• US Class Current: 252/62.51R
• 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: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: C30B 29/60 characterised by shape
• CPC Class Codes: C30B 7/005 Epitaxial layer growth
• 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: G01N 35/0098 involving analyte bound to insoluble magnetic carrier, e.g. using magnetic separation magnetic particles used in immunoassays G01N33/54326; magnetic separation in general B03C
• CPC Class Codes: H01F 1/0054 Coated nanoparticles, e.g. nanoparticles coated with organic surfactant
• 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 428/2995 Silane, siloxane or silicone coating
• CPC Class Codes: Y10T 428/2996 Glass particles or spheres
• CPC Class Codes: Y10T 436/13 Tracers or tags

Abstract

Multifunctional nanocomposites are provided including a core of either a magnetic material or an inorganic semiconductor, and, a shell of either a magnetic material or an inorganic semiconductor, wherein the core and the shell are of differing materials, such multifunctional nanocomposites having multifunctional properties including magnetic properties from the magnetic material and optical properties from the inorganic semiconductor material. Various applications of such multifunctional nanocomposites are also provided.

Claims

1. A composite nanoparticle comprising:

a core of a material selected from the group consisting of a magnetic material and an inorganic semiconductor; and

,

a shell of a material selected from the group consisting of an inorganic semiconductor and a magnetic material, wherein said core and said shell are of differing materials and said composite nanoparticle is characterized as having multifunctional properties including magnetic properties from said magnetic material and optical properties from said inorganic semiconductor material.

3. The composite nanoparticle of claim 1 wherein said core includes multiple layers of at least two active inorganic semiconductors.

4. The composite nanoparticle of claim 1 wherein said shell includes multiple layers of at least two active inorganic semiconductors.

5. The composite nanoparticle of claim 1 wherein said core has at least one dimension of between about 1.5 nm and about 30 nm.

6. The composite nanoparticle of claim 1 wherein said shell is from about 0.3 nm to about 3 nm in thickness.

7. The composite nanoparticle of claim 1 wherein said shell is single crystalline or polycrystalline.

8. The composite nanoparticle of claim 1 wherein said core has a structure selected from the group consisting of spheres, rods, wires, and branched structures.

9. The composite nanoparticle of claim 1 wherein said core is of a magnetic material selected from the group consisting of cobalt, nickel, iron, iron-platinum, iron oxide, and a magnesium iron oxide spinel.

10. The composite nanoparticle of claim 1 wherein said core is of an inorganic semiconductor material selected from the group consisting of Group II-VI compounds, Group II-V compounds, Group III-VI compounds, Group III-V compounds, Group IV-VI compounds, Group I-III-VI compounds, Group II-IV-V compounds, and Group II-IV-VI compounds.

11. The composite nanoparticle of claim 9 wherein said inorganic semiconductor shell is of a material selected from the group consisting of Group II-VI compounds, Group II-V compounds, Group III-VI compounds, Group III-V compounds, Group IV-VI compounds, Group I-III-VI compounds, Group II-IV-V compounds, and Group II-IV-VI compounds.

12. The composite nanoparticle of claim 10 wherein said metallic material shell is of a material selected from the group consisting of cobalt, nickel, iron, iron-platinum, iron oxide, and a magnesium iron oxide spinel.

13. The composite nanoparticle of claim 1 wherein said nanoparticle includes a magnetic material core of cobalt and an inorganic semiconductor shell of cadmium selenide.

14. The composite nanoparticle of claim 1 further including a spacer material between said core and said shell, said spacer material selected from the group consisting of dielectric materials and inorganic semiconductor materials of a thickness or composition so as to function essentially solely as a spacer material.

15. The composite nanoparticle of claim 11 further including a spacer material between said core and said shell, said spacer material selected from the group consisting of dielectric materials and inorganic semiconductor materials of a thickness or composition so as to function essentially solely as a spacer material.

16. The composite nanoparticle of claim 12 further including a spacer material between said core and said shell, said spacer material selected from the group consisting of dielectric materials and inorganic semiconductor materials of a thickness or composition so as to function essentially solely as a spacer material.

17. The composite nanoparticle of claim 1 further including a passivating layer upon said shell layer.

18. The composite nanoparticle of claim 11 further including a passivating layer upon said shell layer.

19. The composite nanoparticle of claim 16 further including a passivating layer upon said shell layer.

2. The composite nanoparticle of claim 1 including a multiplicity of nanoparticles wherein said cores have a monodisperse size distribution.

20. A process of forming composite nanoparticles, each composite nanoparticle including a core of a material selected from the group consisting of a magnetic material and an inorganic semiconductor, and, a shell of a material selected from the group consisting of an inorganic semiconductor and a magnetic material, wherein said core and said shell are of differing materials, the process comprising:

suspending or solvating nanoparticles of either a magnetic material and an inorganic semiconductor material within a liquid medium;

introducing precursors for either (i) a magnetic material where said core is of an inorganic semiconductor material or (ii) an inorganic semiconductor material where said core is of a magnetic material into the liquid medium; and

,

reacting said precursors under conditions capable of obtaining deposition wherein a shell is formed on said cores.

21. The process of claim 20 wherein said cores have at least one dimension between about 1.5 nm and about 30 nm.

22. The process of claim 20 wherein said shell is from about 0.3 nm to about 3 nm in thickness.

23. The process of claim 20 wherein said shell is single crystalline or polycrystalline.

24. The process of claim 20 wherein said core has a structure selected from the group consisting of spheres, rods, wires, and branched structures.

25. The process of claim 20 wherein said magnetic material core is of a material selected from the group consisting of cobalt, nickel, iron, iron-platinum, iron oxide, and a magnesium iron oxide spinel.

26. The process of claim 20 wherein said inorganic semiconductor shell is of a material selected from the group consisting of Group II-VI compounds, Group II-V compounds, Group III-VI compounds, Group III-V compounds, Group IV-VI compounds, Group I-III-VI compounds, Group II-IV-V compounds, and Group II-IV-VI compounds.

27. The process of claim 20 wherein said core is a magnetic material core of cobalt and said shell is inorganic semiconductor material of cadmium selenide.

28. The process of claim 27 wherein said conditions capable of forming an inorganic semiconductor shell on said magnetic material nanoparticles include reaction temperatures from about 120°

C. to about 200°

C.

28-1. A method of dual imaging a sample comprising:

attaching a composite nanoparticle to said sample, said composite nanoparticle including (i)a core of a material selected from the group consisting of a magnetic material and an inorganic semiconductor; and

, (ii) a shell of a material selected from the group consisting of an inorganic semiconductor and a magnetic material, wherein said core and said shell are of differing materials and said composite nanoparticle is characterized as having multifunctional properties including magnetic properties from said magnetic material and optical properties from said inorganic semiconductor material;

analyzing said sample through said optical properties of said composite nanoparticle;

analyzing said sample through said magnetic properties of said composite nanoparticle.

29. A method of detecting and analyzing biomolecules comprising:

labeling biomolecules with a composite nanoparticle including (i)a core of a material selected from the group consisting of a magnetic material and an inorganic semiconductor; and

, (ii) a shell of a material selected from the group consisting of an inorganic semiconductor and a magnetic material, wherein said core and said shell are of differing materials and said composite nanoparticle is characterized as having multifunctional properties including magnetic properties from said magnetic material and optical properties from said inorganic semiconductor material;

manipulating said biomolecules through said magnetic properties of said composite nanoparticles; and

,

analyzing said biomolecules through said optical properties of said composite nanoparticle.

29-2. A method of detecting and treating selected biological cells comprising:

labeling a binding agent with a composite nanoparticle including (i)a core of a material selected from the-group consisting of a magnetic material and an inorganic semiconductor; and

, (ii) a shell of a material selected from the group consisting of an inorganic semiconductor and a magnetic material, wherein said core and said shell are of differing materials and said composite nanoparticle is characterized as having multifunctional properties including magnetic properties from said magnetic material and optical properties from said inorganic semiconductor material, said binding agent having an affinity for a target biological cell;

analyzing said optical properties of said composite nanoparticle to determine location of the composite nanoparticle at said target biological cell; and

,

manipulating said target biological cell through said magnetic properties of said composite nanoparticles to effect a change in said target biological cell.