**2.2. Synthesis of CdS quantum dots**

In this case, the synthesis of the nanostructured CdS quantum dots was performed using a metal cadmium foil, which is 0.5 mm thick (99.99%) from Aldrich Company as a target for the Cd ion source production and thiosulfate and thioglycerol from Merck company as a sulfur source. The cadmium metal foil was washed with a mixture of H2O:HNO3 1:1 (v/v) to remove the oxide layer, followed by distilled water and acetone washing under ultrasound bath for 5 min.

The Cd foil was immersed in a Beaker (50 ml) filled with aqueous solution of thiosulfate (5, 7, 9, 12 and 15 mmols ) and thioglycerol (5 mmols) and ablated for 5 min with the second harmonic order light pulse of a Nd:YAG laser. Soon after the ablation starts, the solution changes its color from transparent to yellow as an indicator that the reaction is taking place. Finally, the products were centrifuged and washed several times with acetone and the material was collected for characterization [19].
