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