Fluorescent nanocomposite

Patent metadata

Field	Value
Publication number	US-10982138-B2
Application number	US-201715836784-A
Country	US
Kind code	B2
Filing date	Dec 8, 2017
Priority date	Dec 8, 2017
Publication date	Apr 20, 2021
Grant date	Apr 20, 2021

Abstract

The present invention relates to a method for forming a nanocomposite having a core-shell structure, the method comprising the steps of: forming a core comprising a first fluorophore capable of aggregation induced emission, and depositing a second fluorophore capable of aggregation caused quenching onto the surface of the core to form a shell at least partially surrounding the core. The present invention also relates to a nanocomposite obtained by said method, and a method of altering the fluorescence of said nanocomposite. The nanocomposite may exhibit dual emission colours and opposite aggregation fluorescent behaviours.

First claim

What is claimed is:

1. A method for forming a nanocomposite having a core-shell structure, the method comprising the steps of:
forming a core comprising a first fluorophore capable of aggregation induced emission, wherein the first fluorophore is a nanocluster comprising a metal formed by contacting a metal salt with a reductant, and the metal is selected from the group consisting of gold, silver, platinum, copper and any mixture thereof, and
depositing a second fluorophore on the surface of the core to form a shell at least partially surrounding the core, by contacting the core with an oxidant comprising a benzoquinone and a biomolecule comprising a thiol group and a primary amine group, wherein the second flurophore is an organic fluorophore comprising a benzothiazine moiety that is capable of aggregation caused quenching,
wherein the molar concentration ratio of metal salt:reductant is in the range of about 2:3 to about 3:2 and the molar concentration ratio of reductant:biomolecule is about 1:4 to about 1:2; and
the first fluorophore and the second fluorophore emit fluorescence at different wavelengths.

2. The method according to claim 1 , wherein the nanocluster has a diameter of less than 2 nm.

3. The method according to claim 1 , wherein the biomolecule is an amino acid or a peptide.

4. The method according to claim 3 , wherein the reductant is 1,4-hydroquinone.

5. The method according to claim 3 , wherein the oxidant is 1,4-benzoquinone or a derivative thereof, and the peptide is a peptide comprising Cys or is Cys-Gly, or the amino acid is Cys.

6. The method according to claim 3 , wherein the forming step and depositing step are performed simultaneously, and comprises contacting the metal salt, the reductant, the oxidant and the biomolecule in a single reaction vessel to form a mixture.

7. The method according to claim 6 , wherein the metal salt, reductant and biomolecule are contacted at a concentration in the range of about 0.5 mM to about 15 mM.

8. The method according to claim 6 , further comprising a step of adding a base to adjust the pH of the mixture to be in the range of about 11 to about 12.

9. The method according to claim 1 , wherein the forming step and/or the depositing step is performed in aqueous solution.

10. The method according to claim 1 , wherein the forming step and depositing step are performed simultaneously or sequentially.

11. The method according to claim 1 , wherein the forming step and/or the depositing step are performed for a duration in the range of about 18 hours to about 30 hours.

12. The method according to claim 1 , further comprising the step of purifying the nanocomposite by dialysis.

13. The method according to claim 12 , wherein the dialysis is performed at a molecular weight cut-off (MWCO) in the range of about 4 kDa to about 8 kDa.

14. A nanocomposite obtained by the method of claim 1 .

15. A method for altering the fluorescence of a nanocomposite having a core-shell structure, the method comprising the step of
changing an aggregation state of the core-shell nanocomposite, wherein the core of the nanocomposite comprises a first fluorophore capable of aggregation induced emission, wherein the first fluorophore is formed by contacting a metal salt with a reductant, and the metal is selected from the group consisting of gold, silver, platinum, copper and any mixture thereof, and the shell of the nanocomposite comprises a second fluorophore deposited on the surface of the core by contacting the core with an oxidant comprising a benzoquinone and a biomolecule comprising a thiol group and a primary amine group so that the shell at least partially surrounding the core, wherein the second flurophore is an organic fluorophore comprising a benzothiazine moiety that is capable of aggregation caused quenching,
wherein the molar concentration ratio of metal salt:reductant is in the range of about 2:3 to about 3:2 and the molar concentration ratio of reductant:biomolecule is about 1:4 to about 1:2; and
the first fluorophore and the second fluorophore emit fluorescence at different wavelengths.

Assignees

• Agency Science Tech & Res

Inventors

• Yu Yong
• Tan Yen Nee

Classifications

• C09K11/06

  containing organic luminescent materials · CPC title

• C09K2211/1018

  Heterocyclic compounds · CPC title

• C09K11/58 Primary

  containing copper, silver or gold · CPC title