PROCEDURE

1. 5.0 mmol of Thioglycolic Acid was dissolved in 10 ml of Toluene.

2. 1.0 g of Tetramethylammonium Hydroxide Pentahydrate was added to the solution.

3. 1.0 ml of the Quantum Dots was added to the solution and allowed to stand at room temperature for 48 hours.

4. The separation of a red and a colorless layer indicated successful ligand exchange. The red layer comprises coated Quantum Dots dissolved in water, while the colorless layer comprises Toluene.

5. Steps 1 to 4 were repeated with 11-Mercaptoundecanoic Acid, Cystamine, and 11-Amino-1-Undecanethiol.

After the mixture is left to stand for 48 hours, the separation of a red layer and a colorless layer would indicate successful ligand exchange.

 

The red layer comprises an aqueous solution of the ligand-exchanged Quantum Dots while the colorless layer comprises Toluene.