A Simple Entropic-Driving Separation Procedure of Low-Size Silver Clusters, Through Interaction with DNA

Synthesis and purification of metal clusters without strong binding agents by wet chemical methods are very attractive for their potential applications in many research areas. However, especially challenging is the separation of uncharged clusters with only a few number of atoms, which renders the usual techniques very difficult to apply. Herein, we report the first efficient separation of Ag₂ and Ag₃ clusters using the different entropic driving forces when such clusters interact with DNA, into which Ag₃ selectively intercalates. After sequential dialysis of the samples and denaturalizing the DNA-Ag₃ complex, pure Ag₂ can be found in the dialysate after extensive dialysis. Free Ag₃ is recovered after DNA denaturation.