Core-shell nanoparticle and method of generating an optical signal using the same

Patent metadata

Field	Value
Publication number	US-9481827-B2
Application number	US-201514932119-A
Country	US
Kind code	B2
Filing date	Nov 4, 2015
Priority date	Nov 4, 2014
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

A core-shell nanoparticle is provided. The core-shell nanoparticle has a core comprising a metal fluoride doped with a first sensitizer and a shell surrounding the core, wherein the shell comprises a first layer comprising the metal fluoride doped with a second sensitizer and a first activator, and a second layer comprising the metal fluoride doped with a third sensitizer and a second activator, wherein the first activator and the second activator are different, and each is independently selected from the group consisting of Tm 3+ , Ho 3+ , and combinations thereof. A method of generating an optical signal using the core-shell nanoparticle and a method of preparing the core-shell nanoparticle is also provided.

First claim

The invention claimed is:

1. A core-shell nanoparticle having a core comprising a metal fluoride doped with a first sensitizer and a shell surrounding the core, wherein the shell comprises
a) a first layer comprising the metal fluoride doped with a second sensitizer and a first activator, and
b) a second layer comprising the metal fluoride doped with a third sensitizer and a second activator,

wherein the first activator and the second activator are different, and each is independently selected from the group consisting of Tm 3+ , Ho 3+ , and combinations thereof.

2. The core-shell nanoparticle according to claim 1 , wherein the metal fluoride is selected from the group consisting of NaYF 4 , CaF 2 , NaGdF 4 , NaLuF 4 , and combinations thereof.

3. The core-shell nanoparticle according to claim 1 , wherein the first sensitizer, the second sensitizer, and the third sensitizer are independently selected from the group consisting of Yb 3+ , Nd 3+ , and combinations thereof.

4. The core-shell nanoparticle according to claim 1 , wherein the first sensitizer comprises at least one of Yb 3+ or Nd 3+ .

5. The core-shell nanoparticle according to claim 1 , wherein total amount of the first sensitizer in the core and the second sensitizer in the first layer is in the range of about 5 mol % to about 40 mol %.

6. The core-shell nanoparticle according to claim 1 , wherein the first activator comprises Tm 3+ .

7. The core-shell nanoparticle according to claim 6 , wherein amount of the first activator in the first layer is in the range of about 0.1 mol % to about 1 mol %.

8. The core-shell nanoparticle according to claim 1 , wherein the first layer is disposed directly on the core.

9. The core-shell nanoparticle according to claim 1 , wherein the second activator comprises Ho 3+ .

10. The core-shell nanoparticle according to claim 9 , wherein amount of the second activator in the second layer is in the range of about 1 mol % to about 10 mol %.

11. The core-shell nanoparticle according to claim 1 , wherein amount of the third sensitizer in the second layer is in the range of about 5 mol % to about 40 mol %.

12. The core-shell nanoparticle according to claim 1 , wherein at least one of the first layer or the second layer further comprises Gd 3+ , Ce 3+ , or their combination.

13. The core-shell nanoparticle according to claim 1 , wherein the shell further comprises at least one of a) a first passivating layer disposed between the first layer and the second layer, or b) a second passivating layer disposed on an outermost layer of the shell.

14. The core-shell nanoparticle according to claim 13 , wherein the first passivating layer and the second passivating layer comprises the metal fluoride.

15. The core-shell nanoparticle according to claim 1 , wherein the core further comprises the first activator.

16. A method of generating an optical signal, the method comprising
a) irradiating a core-shell nanoparticle with radiation, the core-shell nanoparticle having a core comprising a metal fluoride doped with a first sensitizer and a shell surrounding the core, wherein the shell comprises
i. a first layer comprising the metal fluoride doped with a second sensitizer and a first activator, and
ii. a second layer comprising the metal fluoride doped with a third sensitizer and a second activator,

wherein the first activator and the second activator are different, and each is independently selected from the group consisting of Tm 3+ , Ho 3+ , and combinations thereof; and
b) controlling at least one of a wavelength or a duration of the radiation to generate the optical signal from the core-shell nanoparticle.

17. The method according to claim 16 , wherein the radiation is a pulsed or a continuous laser radiation.

18. The method according to claim 17 , wherein the laser radiation has a wavelength of about 800 nm or about 980 nm.

19. The method according to claim 16 , wherein wavelength of the optical signal is one or more wavelengths in a range from about 380 nm to about 780 nm.

20. A method of preparing a core-shell nanoparticle, the method comprising
a) providing a nanoparticle comprising a metal fluoride doped with a first sensitizer, and
b) forming a shell having a first layer comprising the metal fluoride doped with a second sensitizer and a first activator and a second layer comprising the metal fluoride doped with a third sensitizer and a second activator on the nanoparticle,

wherein the first activator and the second activator are different, and each is independently selected from the group consisting of Tm 3+ , Ho 3+ , and combinations thereof.

Assignees

• Agency Science Tech & Res
• Nat Univ Singapore

Inventors

• Liu Xiaogang
• Yang Weifeng
• Deng Renren

Classifications

• G01N21/6428

  Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" (in vivo A61B5/00; immunoassay G01N33/53) · CPC title

• C09K11/7772

  Halogenides (C09K11/7767 takes precedence) · CPC title

• C09K11/7773

  with alkali or alkaline earth metal · CPC title

• G01N21/64

  Fluorescence; Phosphorescence · CPC title

• C09K11/77

  containing rare earth metals · CPC title