Microspheres including nanoparticles

• US 20060019098A1
• Filed: 07/26/2004
• Published: 01/26/2006
• Est. Priority Date: 07/26/2004
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Zimmer, John P., Chan, YinThai, Bawendi, Moungi G.
• Granted Patent: US 7,229,690 B2
• Time in Patent Office: Days
• US Class Current: 428/403
• CPC Class Codes: B01J 13/02 Making microcapsules or microballoons for medical preparations A61K9/50
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C09K 11/02 Use of particular materials as binders, particle coatings or suspension media therefor
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/565 with zinc cadmium
• CPC Class Codes: C09K 11/883 with zinc or cadmium
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/778 within specified host or matrix material, e.g. nanocomposite films
• CPC Class Codes: Y10S 977/779 Possessing nanosized particles, powders, flakes, or clusters other than simple atomic impurity doping
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]
• 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.]

Abstract

A microparticle can include a central region and a peripheral region. The peripheral region can include a nanoparticle, such as a metal nanoparticle, a metal oxide nanoparticle, or a semiconductor nanocrystal. The microparticle can be a member of a monodisperse population of particles.

Claims

1. A microsphere comprising:

a central region; and

a first peripheral layer on a surface of the central region, the first peripheral layer including a first nanoparticle dispersed within the layer.

2. The microsphere of claim 1, wherein the central region includes an inorganic material.

3. The microsphere of claim 2, wherein the central region includes silicon.

4. The microsphere of claim 1, wherein the first peripheral region includes an inorganic material.

5. The microsphere of claim 4, wherein the first peripheral region includes silicon or titanium.

6. The microsphere of claim 1, wherein the microsphere has a diameter of less than 500 micrometers.

7. The microsphere of claim 1, wherein the microsphere has a diameter of less than 10 micrometers.

8. The microsphere of claim 1, wherein the microsphere has a diameter of less than 1 micrometer.

9. The microsphere of claim 1, wherein the central region is substantially free of nanoparticles.

10. The microsphere of claim 1, wherein the first nanoparticle is a metal nanoparticle, a metal oxide nanocrystal, or a semiconductor nanocrystal.

11. The microsphere of claim 1, wherein the first nanoparticle is a semiconductor nanocrystal.

12. The microsphere of claim 11, wherein the semiconductor nanocrystal includes a core including a first semiconductor material.

13. The microsphere of claim 12, wherein the semiconductor nanocrystal further includes a shell overcoating the core, the shell including a second semiconductor material.

14. The microsphere of claim 13, wherein the first semiconductor material is a Group II-VI compound, a Group II-V compound, a Group III-VI compound, a Group III-V compound, a Group IV-VI compound, a Group I-III-VI compound, a Group II-IV-VI compound, or a Group II-IV-V compound.

15. The microsphere of claim 14, wherein the first semiconductor material is ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, GaSe, InN, InP, InAs, InSb, TlN, TIP, TlAs, TlSb, PbS, PbSe, PbTe, or mixtures thereof.

16. The microsphere of claim 15, wherein the second semiconductor material is ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdSe, CdTe, MgO, MgS, MgSe, MgTe, HgO, HgS, HgSe, HgTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, TlN, TlP, TlAs, TiSb, TlSb, PbS, PbSe, PbTe, or mixtures thereof.

17. The microsphere of claim 11, wherein the microsphere includes a plurality of semiconductor nanocrystals having a rms deviation in diameter of no greater than 5%.

18. The microsphere of claim 10, further comprising a ligand having affinity for a surface of the first nanoparticle.

19. The microsphere of claim 18, wherein the ligand is covalently linked to the first peripheral region.

20. The microsphere of claim 1, wherein the central region is substantially spherical in shape.

21. The microsphere of claim 1, wherein the microsphere is a member of a population of microsphere having a rms deviation in diameter of no greater than 10%.

22. The microsphere of claim 1, further comprising a second peripheral region on a surface of the first peripheral region.

23. The microsphere of claim 22, wherein the second peripheral region includes an inorganic material.

24. The microsphere of claim 23, wherein the second peripheral region includes silicon or titanium.

25. The microsphere of claim 22, wherein the second peripheral region includes a second nanoparticle.

26. The microsphere of claim 25, wherein the second nanoparticle is a metal nanoparticle, a metal oxide nanocrystal, or a semiconductor nanocrystal.

27. The microsphere of claim 25, wherein the first nanoparticle is a fluorescent nanoparticle and the second nanoparticle is a fluorescent nanoparticle.

28. The microsphere of claim 27, wherein the first nanoparticle has a fluorescence emission distinguishable from a fluorescence emission of the second nanoparticle.

29. A microsphere comprising:

a central region including a first inorganic material; and

a peripheral region on a surface of the central region, the peripheral region including a second inorganic material and a semiconductor nanocrystal covalently linked to the second inorganic material.

30. A population of microspheres comprising a member microsphere including:

a central region including a first inorganic material; and

a first peripheral region on a surface of the central region, the first peripheral region including a second inorganic material and a first nanoparticle.

31. The population of claim 30, wherein the first inorganic material includes silicon.

32. The population of claim 30, wherein the second inorganic material includes silicon or titanium.

33. The population of claim 30, wherein the member microsphere has a diameter of less than 500 micrometers.

34. The population of claim 30, wherein the member microsphere has a diameter of less than 10 micrometers.

35. The population of claim 30, wherein the member microsphere has a diameter of less than 1 micrometer.

36. The population of claim 30, wherein the central region is substantially free of nanoparticles.

37. The population of claim 30, wherein the first nanoparticle is a metal nanoparticle, a metal oxide nanocrystal, or a semiconductor nanocrystal.

38. The population of claim 37, wherein the first nanoparticle is a semiconductor nanocrystal.

39. The population of claim 38, wherein the semiconductor nanocrystal includes a core including a first semiconductor material.

40. The population of claim 39, wherein the semiconductor nanocrystal further includes a shell overcoating the core, the shell including a second semiconductor material.

41. The population of claim 40, wherein the first semiconductor material is a Group II-VI compound, a Group II-V compound, a Group III-VI compound, a Group III-V compound, a Group IV-VI compound, a Group I-III-VI compound, a Group II-IV-VI compound, or a Group II-IV-V compound.

42. The population of claim 41, wherein the first semiconductor material is ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, GaSe, InN, InP, InAs, InSb, TlN, TlP, TlAs, TlSb, PbS, PbSe, PbTe, or mixtures thereof.

43. The population of claim 42, wherein the second semiconductor material is ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdSe, CdTe, MgO, MgS, MgSe, MgTe, HgO, HgS, HgSe, HgTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, TlN, TlP, TlAs, TlSb, TlSb, PbS, PbSe, PbTe, or mixtures thereof.

44. The population of claim 39, wherein the member microsphere includes a plurality of semiconductor nanocrystals having a rms deviation in diameter of no greater than 5%.

45. The population of claim 37, wherein the member microsphere further comprises a ligand having affinity for a surface of the first nanoparticle.

46. The population of claim 45, wherein the ligand is covalently linked to the second inorganic material.

47. The population of claim 30, wherein the central region is substantially spherical in shape.

48. The population of claim 30, wherein the population of microspheres has a rms deviation in diameter of no greater than 10%.

49. The population of claim 30, wherein the member microsphere further includes a second peripheral region on a surface of the first peripheral region.

50. The population of claim 49, wherein the second peripheral region includes an inorganic material.

51. The population of claim 50, wherein the second peripheral region includes silicon or titanium.

52. The population of claim 49, wherein the second peripheral region includes a second nanoparticle.

53. The population of claim 52, wherein the second nanoparticle is a metal nanoparticle, a metal oxide nanocrystal, or a semiconductor nanocrystal.

54. A family of microsphere populations comprising:

a first population of microspheres, wherein each microsphere in the first population includes a central region; and

a peripheral region on a surface of the central region, the peripheral region including a first nanoparticle; and

a second population of microspheres, wherein each microsphere in the second population includes a central region; and

a peripheral region on a surface of the central region, the peripheral region including a second nanoparticle.

55. The family of claim 54, wherein the first nanoparticle is a fluorescent nanoparticle.

56. The family of claim 55, wherein the second nanoparticle is a fluorescent nanoparticle.

57. The family of claim 56, wherein the first population has a fluorescence emission distinguishable from a fluorescence emission of the second population.

58. The family of claim 54, wherein the microspheres of the first population have a rms deviation in diameter of no greater than 10%.

59. The family of claim 58, wherein the microspheres of the second population have a rms deviation in diameter of no greater than 10%.

60. The family of claim 59, wherein the microspheres of the first population have an average diameter distinct from an average diameter of the microspheres of the second population.

61. The family of claim 54, wherein the microspheres of the first population and the microspheres of the second population have distinct fluorescence emission wavelengths.

62. The family of claim 60, wherein the first nanoparticle is a fluorescent nanoparticle and the second nanoparticle is a fluorescent nanoparticle.

63. The family of claim 62, wherein the microspheres of the first population and the microspheres of the second population have distinct fluorescence emission wavelengths.

64. The family of claim 54, wherein the microspheres of the first population have an average diameter of less than 500 micrometers.

65. The family of claim 54, wherein the microspheres of the first population have an average diameter of less than 10 micrometers.

66. The family of claim 54, wherein the microspheres of the first population have an average diameter of less than 1 micrometer.

67. The family of claim 66, wherein the microspheres of the second population have an average diameter of less than 1 micrometer.

68. A method of making a microsphere comprising:

providing a particle including a first inorganic material;

contacting the particle with a precursor to a second inorganic material and a first nanoparticle; and

forming a peripheral region on a surface of the particle, the peripheral region including the second inorganic material and the first nanoparticle.

69. The method of claim 68, wherein the first inorganic material includes silicon.

70. The method of claim 68, wherein the second inorganic material includes silicon or titanium.

71. The method of claim 68, wherein the first nanoparticle is a metal nanoparticle, a metal oxide nanocrystal, or a semiconductor nanocrystal.

72. The method of claim 68, wherein the first nanoparticle is a semiconductor nanocrystal.

73. The method of claim 72, wherein the semiconductor nanocrystal includes a core including a first semiconductor material.

74. The method of claim 73, wherein the semiconductor nanocrystal further includes a shell overcoating the core, the shell including a second semiconductor material.

75. The method of claim 74, wherein the first semiconductor material is a Group II-VI compound, a Group II-V compound, a Group III-VI compound, a Group III-V compound, a Group IV-VI compound, a Group I-III-VI compound, a Group II-IV-VI compound, or a Group II-IV-V compound.

76. The method of claim 75, wherein the first semiconductor material is ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, GaSe, InN, InP, InAs, InSb, TlN, TIP, TlAs, TlSb, PbS, PbSe, PbTe, or mixtures thereof.

77. The method of claim 76, wherein the second semiconductor material is ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdSe, CdTe, MgO, MgS, MgSe, MgTe, HgO, HgS, HgSe, HgTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, TlN, TlP, TlAs, TlSb, TlSb, PbS, PbSe, PbTe, or mixtures thereof.

78. The method of claim 72, wherein the semiconductor nanocrystal is a member of a population of semiconductor nanocrystals having a rms deviation in diameter of no greater than 5%.

79. The method of claim 68, wherein the semiconductor nanocrystal further includes a ligand having affinity for a surface of the first nanoparticle.

80. The method of claim 79, wherein the ligand is capable of reacting with the precursor to the second inorganic material.

81. The method of claim 68, wherein the particle including the first inorganic material is a member of a population of particles having a rms deviation in diameter of no greater than 10%.

82. The method of claim 68, wherein the particle including the first inorganic material is substantially spherical in shape.

83. The method of claim 68, wherein the particle including the first inorganic material has a diameter of less than 500 micrometers.

84. The method of claim 68, wherein the particle including the first inorganic material has a diameter of less than 10 micrometers.

85. The method of claim 68, wherein the particle including the first inorganic material has a diameter of less than 1 micrometer.

86. The method of claim 68, further comprising forming the particle including the first inorganic material.

87. The method of claim 85, further comprising forming the particle including the first inorganic material.

88. A method of making a family of microsphere populations comprising:

selecting a first nanoparticle and a second nanoparticle;

forming a first population of microspheres, the first population including a first member microsphere including

a central region including a first inorganic material; and

a peripheral region on a surface of the central region, the peripheral region including a second inorganic material and the first nanoparticle; and

forming a second population of microspheres, the second population including a second member microsphere including

a central region including a third inorganic material; and

a peripheral region on a surface of the central region, the peripheral region including a fourth inorganic material and the second nanoparticle.

89. The method of claim 88, wherein the first nanoparticle is a fluorescent nanoparticle.

90. The method of claim 89, wherein the second nanoparticle is a fluorescent nanoparticle.

91. The method of claim 90, wherein the first member microsphere has a fluorescence emission distinguishable from a fluorescence emission of the second member microsphere.

92. The method of claim 91, wherein the first member microsphere has a fluorescence wavelength distinguishable from a fluorescence wavelength of the second member microsphere.

93. The method of claim 91, wherein the first member microsphere has a fluorescence intensity distinguishable from a fluorescence intensity of the second member microsphere.

94. A method of tracking microspheres comprising:

viewing a first microsphere including a central region and a peripheral region on a surface of the central region, the peripheral region including a first nanoparticle; and

viewing a second microsphere including a central region and a peripheral region on a surface of the central region, the peripheral region including a second nanoparticle.

95. The method of claim 94, wherein the first nanoparticle is a fluorescent nanoparticle.

96. The method of claim 95, wherein the second nanoparticle is a fluorescent nanoparticle.

97. The method of claim 95, wherein viewing the first microsphere includes observing a fluorescence emission from the first microsphere.

98. The method of claim 96, wherein the first microsphere has a fluorescence emission distinguishable from a fluorescence emission of the second microsphere.

99. The method of claim 94, wherein the first microsphere has a size distinguishable from a size of the second microsphere.

100. The method of claim 94, wherein the first microsphere includes a central region including an inorganic material.

101. The method of claim 99, wherein the first microsphere includes a peripheral region including an inorganic material.

102. The method of claim 100, wherein the first microsphere includes a semiconductor nanocrystal.