Removal of the A₁₀ adenosine in a DNA-stabilized Ag₁₆ nanocluster

The role of the terminal adenosine (A₁₀) on the spectroscopic and structural properties of a previously described DNA-stabilized Ag₁₆ nanocluster (DNA:Ag₁₆NC) is presented. In the original DNA:Ag₁₆NCs (5'-CACCTAGCGA-3'), the A₁₀ nucleobase was involved in an Ag⁺-mediated interaction with an A₁₀ in a neighboring asymmetric unit, and did not interact with the Ag₁₆NC. Therefore, we synthesized AgNCs embedded in the corresponding 9-base sequence in order to investigate the crystal structure of these new DNA-A₁₀:Ag₁₆NCs 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 Ag₁₆NCs. 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.