Removal of the A(10) adenosine in a DNA-stabilized Ag(16) nanocluster

The role of the terminal adenosine (A(10)) on the spectroscopic and structural properties of a previously described DNA-stabilized Ag(16) nanocluster (DNA:Ag(16)NC) is presented. In the original DNA:Ag(16)NCs (5′-CACCTAGCGA-3′), the A(10) nucleobase was involved in an Ag(+)-mediated interaction with an A(10) in a neighboring asymmetric unit, and did not interact with the Ag(16)NC. Therefore, we synthesized AgNCs embedded in the corresponding 9-base sequence in order to investigate the crystal structure of these new DNA-A(10):Ag(16)NCs and analyze the photophysical properties of the solution and crystalline state. The X-ray crystallography and spectroscopic measurements revealed that the 3′-end adenosine has little importance with respect to the photophysics and structure of the Ag(16)NCs. Additionally, the new crystallographic data was recorded with higher spatial resolution leading to a more detailed insight in the interactions between the nucleotides and Ag atoms.