Metal nanoshells

• US 6,344,272 B1
• Filed: 03/11/1998
• Issued: 02/05/2002
• Est. Priority Date: 03/12/1997
• Status: Expired due to Term

• Current Assignee: Rice University
• Original Assignee: Rice University
• Inventors: Halas, Nancy J., Oldenburg, Steven J., Averitt, Richard D.
• Primary Examiner(s): Krynski, William
• Assistant Examiner(s): Shewareged, B.
• Application Number:
  US09/038,377
• Time in Patent Office: 1,427 Days
• Field of Search: 428/403, 428/404, 428/913, 252/478, 252/518, 252/520, 252/587
• US Class Current: 428/403
• CPC Class Codes: A61K 41/0042 Photocleavage of drugs in vivo, e.g. cleavage of photolabile linkers in vivo by UV radiation for releasing the pharmacologically-active agent from the administered agent; photothrombosis or photoocclusion
• CPC Class Codes: B01J 13/02 Making microcapsules or microballoons for medical preparations A61K9/50
• CPC Class Codes: B22F 1/054 Nanosized particles
• CPC Class Codes: B22F 1/056 Submicron particles having a size above 100 nm up to 300 nm
• CPC Class Codes: B22F 1/18 Non-metallic particles coated with metal
• 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 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 5/00 Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery
• CPC Class Codes: C01P 2002/82 by IR- or Raman-data
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C01P 2004/12 with a cylindrical shape
• CPC Class Codes: C01P 2004/32 Spheres
• CPC Class Codes: C01P 2004/38 cube-like
• CPC Class Codes: C01P 2004/50 Agglomerated particles
• CPC Class Codes: C01P 2004/54 Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2004/80 Particles consisting of a mixture of two or more inorganic phases
• CPC Class Codes: C01P 2006/22 : Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
• CPC Class Codes: C01P 2006/33 : Phase transition temperatures
• CPC Class Codes: C01P 2006/40 : Electric properties
• CPC Class Codes: C01P 2006/60 : Optical properties, e.g. expressed in CIELAB-values
• CPC Class Codes: C08K 9/02 : Ingredients treated with inorganic substances
• CPC Class Codes: C09C 1/3054 : Coating
• CPC Class Codes: C09C 1/3081 : Treatment with organo-silicon compounds
• CPC Class Codes: C09C 1/309 : Combinations of treatments provided for in groups C09C1/3009 - C09C1/3081
• CPC Class Codes: C09K 3/00 : Materials not provided for elsewhere
• CPC Class Codes: G01N 21/658 : enhancement Raman, e.g. surface plasmons
• CPC Class Codes: G02F 1/355 : characterised by the materials used
• CPC Class Codes: Y10S 428/913 : Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10S 977/777 : Metallic powder or flake
• CPC Class Codes: Y10S 977/832 : having specified property, e.g. lattice-constant, thermal expansion coefficient
• CPC Class Codes: Y10S 977/835 : Chemical or nuclear reactivity/stability of composition or compound forming nanomaterial
• 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

The present invention is for particulate compositions and methods for producing them that can absorb or scatter electromagnetic radiation. The particles are homogeneous in size and are comprised of a nonconducting inner layer that is surrounded by an electrically conducting material. The ratio of the thickness of the nonconducting layer to the thickness of the outer conducting shell is determinative of the wavelength of maximum absorbance or scattering of the particle. Unique solution phase methods for synthesizing the particles involve linking clusters of the conducting atoms, ions, or molecules to the nonconducting inner layer by linear molecules. This step can be followed by growth of the metal onto the clusters to form a coherent conducting shell that encapsulates the core.

Claims

1. A nanoparticle comprising at least one non-conducting core layer and at least one conducting shell layer, said shell layer immediately adjacent to and independently layered upon said core layer, wherein thickness of said shell layer is not limited to account for the bulk dielectric properties of a material comprising said conducting shell layer, said nanoparticle having a wavelength extinction maximum between 300 nm and 20 μ

m.

2. The nanoparticle of claim 1 wherein said conducting shell layer comprises a metal.

3. The nanoparticle of claim 2 wherein said metal is comprised of a metal selected from the group consisting of the coinage metals, noble metals, transition metals, and synthetic metals.

4. The nanoparticle of claim 1 wherein said conducting shell layer comprises an organic conducting material.

5. The nanoparticle of claim 1 wherein said conducting shell layer comprises a metal alloy.

6. The nanoparticle of claim 1 wherein said nanoparticle comprises at least one additional non-conducting core layers in an alternating sequence with additional conducting shell layers.

7. The nanoparticle of claim 1 wherein said non-conducting core layer comprises a dielectric material.

8. The nanoparticle of claim 7 wherein said dielectric material is selected from the group consisting of silicon dioxide, titanium dioxide, PMMA, polystyrene, and dendrimers.

9. The nanoparticle of claim 1 wherein said non-conducting core layer comprises a semi-conducting material.

10. The nanoparticle of claim 1 wherein said non-conducting core layer comprises an organic molecule or an organic supermolecular structure.

11. The nanoparticle of claim 1 wherein said non-conducting core layer comprises a mixture of non-conducting materials.

12. The nanoparticle of claim 1 wherein said non-conducting core layer comprises an optically absorbing material.

13. The nanoparticle of claim 1 wherein said non-conducting core layer comprises a fluorescent material.

14. The nanoparticle of claim 1 further comprising an outermost non-conducting core layer bound to an adjacent conducting shell layer.

15. The nanoparticle of claim 1 further comprising a non-conducting layer sandwiched between two conducting layers.

16. The nanoparticle of claim 1 further comprising a conducting layer sandwiched between two non-conducting layers.

17. The nanoparticle of claim 1 wherein the diameter of said nanoparticles varies by less than 100%.

18. The nanoparticle of claim 1 wherein said conducting shell layer coats at least 10% of said non-conducting core layer.

19. The nanoparticle of claim 10 wherein said conducting shell layer coats at least 10% but less than 100% of said non-conducting core layer.

20. The nanoparticle of claim 1 wherein said conducting shell layer completely surrounds said non-conducting core layer.

21. The nanoparticle of claim 1 wherein said conducting shell layer is linked to said non-conducting core layer by a linker molecule.

22. The nanoparticle of claim 1 wherein said nanoparticles is approximately spherical.

23. The nanoparticle of claim 1 wherein said nanoparticle is non-spherical.

24. An x-ray absorbing device comprising the nanoparticle of claim 1.

25. A light detecting device comprising the nanoparticle of claim 1.

26. A chemical sensing device comprising the nanoparticle of claim 1.

27. A bolometer comprising the nanoparticle of claim 1.

28. A microbolometer comprising the nanoparticle of claim 1.

29. A sensing cantilever device comprising the nanoparticle of claim 1.

30. A dopant in an optically active material comprising the nanoparticle of claim 1.

31. A polymer comprising the nanoparticle of claim 1.

32. A photovoltaic solar cell comprising the nanoparticle of claim 1.

33. An infrared detector comprising the nanoparticle of claim 1.

36. A mixture of nanoparticles as in claim 1, said mixture capable of absorbing electromagnetic radiation, said mixture further comprising nanoparticles between approximately 5 nm and 2 μ

m thick.

34. A particle comprising a core that is between 1 nm and 2 μ

m in diameter, said core further comprising silicon dioxide, said core being encapsulated by a layer of a metal that is less than approximately 40 nm thick, said metal comprising gold, wherein said metal is linked to said core through a linker molecule, said particle having a wavelength absorbance maximum between 300 nm and 20 μ

m.

37. The particle of claim 34, wherein said linker molecule further comprises aminopropyltriethoxy silane.

38. The particle of claim 34, wherein said linker molecule further comprises aminopropyltrimethoxy silane.

39. The particle of claim 34, wherein said linker molecule further comprises diaminopropyl diethoxy silane.

40. The particle of claim 34, wherein said linker molecule further comprises 4-aminobutyl dimethylmethoxysilane.

41. The particle of claim 34, wherein said linker molecule further comprises a linker upon which direct reduction of atoms of said metal may be conducted.

42. The particle of claim 34, wherein said linker molecule further comprises diaminopropyl diethoxy silane.

43. The particle of claim 34, wherein said linker molecule further comprises diphenyltriethoxy silane reacted with tetrahydrothiophene(AuCl).

44. The particle of claim 34, wherein said linker molecule further comprises a second non-metallic material.

45. The particle of claim 44, wherein said second non-metallic material further comprises either CdS or CdSe.

46. The particle of any of claims 34 and 44-45, wherein said linker molecule is crosslinked to another linker molecule.

47. The particle of claim 46, wherein said crosslinked linker molecules are crosslinked by a thermal or a photo-induced chemical crosslinking process.

48. The particle of claim 34, wherein said wavelength absorbance maximum is between 500 nm and 10 μ

m.

49. The particle of claim 34, wherein said wavelength absorbance maximum is between 900 nm and 5 μ

m.

35. A particle that absorbs electromagnetic radiation, said particle having a diameter of greater than approximately 1 nm. and comprising at least a first and a second layer, said second layer surrounding said first layer, wherein said first layer comprises a non-conducting material and said second layer comprises a conducting material, and wherein thickness of said second layer is not limited to account for the bulk dielectric properties of a material comprising said second layer.