TERNARY AND QUARTERNARY NANOCRYSTALS, PROCESSES FOR THEIR PRODUCTION AND USES THEREOF

• US 20060110279A1
• Filed: 12/16/2002
• Published: 05/25/2006
• Est. Priority Date: 12/16/2002
• Status: Active Grant

• Current Assignee: Agency For Science Technology and Research, National University of Singapore
• Original Assignee: Agency For Science Technology and Research
• Inventors: Han, Mingyong, Knoll, Wolfgang, Zhong, Xinhua
• Granted Patent: US 7,056,471 B1
• Time in Patent Office: Days
• US Class Current: 420/523
• CPC Class Codes: C30B 29/48 AIIBVI compounds wherein A is Zn, Cd or Hg, and B is S, Se or Te
• CPC Class Codes: C30B 29/605 Products containing multiple oriented crystallites, e.g. columnar crystallites
• CPC Class Codes: C30B 7/00 Single-crystal growth from solutions using solvents which are liquid at normal temperature, e.g. aqueous solutions from molten solvents C30B9/00; by normal or gradient freezing C30B11/00; under a protective fluid C30B27/00

Abstract

The present invention relates to nanocrystals consisting of a homogeneous ternary or quaternary alloy having the composition M1_1-xM2_xA and M1_1-xM2_xA_yB_1-y, respectively, a process for its production, as well as to uses of such nanocrystals such as as short wavelength light-emitting devices, and in the detection of analytes, in particular biomolecules.

Claims

1. A nanocrystal consisting of a homogeneous ternary alloy having the composition selected from the group consisting of Zn_xCd_1-xSe and Zn_xCd_1-xS,

obtainable by a process comprising

i) forming a binary nanocrystal CdSe or CdS by heating a reaction mixture containing the element Cd in a form suitable for the generation of a nanocrystal to a suitable temperature T1, adding at this temperature the element Se or S in a form suitable for the generation of a nanocrystal, heating the reaction mixture for a sufficient period of time at a temperature suitable for forming said binary nanocrystal CdSe or CdS and then allowing the reaction mixture to cool, and

ii) reheating the reaction mixture, without precipitating or isolating the formed binary nanocrystal CdSe or CdS, to a suitable temperature T2, adding to the reaction mixture at this temperature a sufficient quantity of the element Zn in a form suitable for the generation of a nanocrystal, then heating the reaction mixture for a sufficient period of time at a temperature suitable for forming said ternary nanocrystal Zn_xCd_1-xSe or Zn_xCd_1-xS and then allowing the reaction mixture to cool to room temperature, and isolating the ternary nanocrystal Zn_xCd_1-xSe or Zn_xCd_1-xS.

2. The nanocrystal of claim 1 with 0.001<

x<

0.999.

3. The nanocrystal of claim 2 with 0.5<

x<

0.95.

7. The nanocrystal of claim 1 with 0.15<

x<

0.85.

8. The nanocrystal of claim 7 with 0.2<

x<

0.8.

42. The nanocrystal of claim 1 incorporated into a plastic bead.

44. A detection kit containing a nanocrystal as defined in claim 1.

62. A process for detecting an analyte, comprising contacting an analyte with a molecule having a binding affinity for the analyte, the molecule being conjugated to the nanocrystal of claim 1.

63. The nanocrystal of claim 1, wherein the homogenous tenary alloy has the composition Zn_xCd_1-xSe.

64. The nanocrystal of claim 1, wherein the homogenous ternary alloy has the composition Zn_xCd_1-xS.

65. The nanocrystal of claim 1 conjagated to molecule having a binding affinity for a given analyte.

66. The nanocrystal of claim 65, wherein the molecule having a binding affinity for a given analyte has a binding affinity to a biomolecule.

67. The nanocrystal of claim 66, wherein the molecule having a binding affinity for an analyte is a molecule selected from the group consisting of a protein, a peptide, a compound having features of an immunogenic hapten, a nucleic acid, a carbohydrate, and an organic molecule.

68. The nanocrystal of claim 67, wherein the nanocrystal is conjugated to said molecule having a binding activity for an analyte via a linking agent.

4-6. -6. (canceled)

9-41. -41. (canceled)

43. (canceled)

45. (canceled)

46-50. -50. (canceled)

51. A process of producing a nanocrystal consisting of a homogeneous ternary alloy having the composition selected from the group consisting of Zn_xCd_1-xSe and Zn_xCd_1-xS,

said process comprising

i) forming a binary nanocrystal CdSe or CdS by heating a reaction mixture containing the element Cd in a form suitable for the generation of a nanocrystal to a suitable temperature T1, adding at this temperature the element Se or S in a form suitable for the generation of a nanocrystal, heating the reaction mixture for a sufficient period of time at a temperature suitable for forming said binary nanocrystal CdSe or CdS and then allowing the reaction mixture to cool, and

ii) reheating the reaction mixture, without precipitating or isolating the formed binary nanocrystal CdSe or CdS, to a suitable temperature T2, adding to the reaction mixture at this temperature a sufficient quantity of the element Zn in a form suitable for the generation of a nanocrystal, then heating the reaction mixture for a sufficient period of time at a temperature suitable for forming said ternary nanocrystal Zn_xCd_1-xSe or Zn_xCd_1-xS and then allowing the reaction mixture to cool to room temperature, and isolating the ternary nanocrystal Zn_xCd_1-xSe or

52. The process of claim 51, wherein the reaction mixture in i) is allowed to cool to a temperature below 100°

C. after formation of the binary nanocrystal CdSe or CdS.

53. The process of claim 51 with 0.001<

x<

0.999.

54. The process of claim 53 with 0.1<

x<

0.95.

55. The process of claim 51, wherein the homogeneous ternary alloy has the composition Zn_xCd_1-xSe.

56. The process of claim 51 with 0.15<

x<

0.85.

57. The process of claim 56 with 0.2<

x<

0.8.

58. The process of claim 51, wherein the reaction mixture in i) is heated to a temperature T1 between 150°

C. and 400°

C.

59. The process of claim 51, wherein the reaction mixture in ii) is heated to a temperature T2 between 200°

C. and 400°

C.

60. The process of claim 51, wherein in ii) a second quantity of the element Se or S is added for the formation of the ternary nanocrystal.

61. The process of claim 51, wherein the homogeneous ternary alloy has the composition Zn_xCd_1-xS.