Gold and silver quantum clusters in molecular containers and methods for their preparation and use

1. A method of preparing a quantum cluster, the method comprising:

adding a first amount of glutathione to a gold salt, a silver salt, or a mixture thereof to form a mixture;

adding a reducing agent to the mixture to form a precipitate; and

mixing the precipitate with a second amount of glutathione and a cyclodextrin to form the quantum cluster;

wherein the quantum cluster comprises:

Ag m , Au n , or Ag m Au n , wherein m and n are independently from 2 to 100;

one or more of the glutathione molecules bound to the Ag m , Au n , or Ag m Au n ; and

the cyclodextrin partially or wholly surrounding the one or more glutathione molecules bound to the Ag m , Au n , or Ag m Au n ;

wherein the cyclodextrin is selected from the group consisting of unsubstituted α-cyclodextrin, unsubstituted β-cyclodextrin, and unsubstituted γ-cyclodextrin.

2. The method of claim 1 , having a molar ratio of the first amount of glutathione to the amount of the gold salt, the silver salt, or the mixture thereof is about 1:2 to about 1:8.

3. The method of claim 1 , wherein the precipitate comprises a) a quantum cluster of Ag m , Au n , or Ag m Au n , and b) glutathione, wherein m and n are independently from 2 to 100.

4. The method of claim 1 , wherein the gold salt is a trivalent gold source.

5. The method of claim 1 , wherein the reducing agent is NaBH 4 or LiBH 4 .

6. The method of claim 1 , wherein the step of mixing the precipitate with a second amount of glutathione and the cyclodextrin to form the quantum cluster occurs at a temperature of about 70° C.

7. The method of claim 1 , wherein the method comprises

adding a first amount of glutathione to a gold salt to form a mixture;

adding a reducing agent to the mixture to form a precipitate; and

mixing the precipitate with a second amount of glutathione and a cyclodextrin to form the quantum cluster;

wherein the quantum cluster comprises:

Au n , wherein n is independently from 2, 3, 5, 10, or 15;

one or more of the glutathione molecules bound to the Au n ; and

the cyclodextrin partially or wholly surrounding the one or more glutathione molecules bound to the Au n ;

wherein the cyclodextrin is selected from the group consisting of unsubstituted α-cyclodextrin, unsubstituted β-cyclodextrin, and unsubstituted γ-cyclodextrin.

8. The method of claim 7 , wherein the step of mixing the precipitate with a second amount of glutathione and a cyclodextrin to form the quantum cluster occurs at a temperature of about 70° C.

9. The method of claim 7 , wherein in the step of adding a reducing agent to the mixture the reducing agent is NaBH 4 or LiBH 4 .

10. The method of claim 9 , wherein the step of adding the reducing agent to the mixture occurs at a temperature of about 0° C.

11. The method of claim 1 , wherein the method comprises

adding a first amount of glutathione to a gold salt to form a mixture;

adding a reducing agent to the mixture at a temperature of about 0° C. to form a precipitate; and

mixing the precipitate with a second amount of glutathione and a cyclodextrin at a temperature of about 70° C. to form the quantum cluster;

wherein the quantum cluster comprises:

Au n , wherein n is 15;

one or more of the glutathione molecules bound to the Au n ; and

the cyclodextrin partially or wholly surrounding the one or more glutathione molecules bound to the Au n ;

wherein the cyclodextrin is selected from the group consisting of unsubstituted α-cyclodextrin, unsubstituted β-cyclodextrin, and unsubstituted γ-cyclodextrin.

12. The method of claim 11 , wherein in the step of adding a reducing agent to the mixture the reducing agent is NaBH 4 .