Effect of Ectoine on the Conformation and Hybridization of dsDNA in Monolayer Films: A Spectroelectrochemical Study

Lack of long-time stability dsDNA-based supramolecular assemblies is an important issue that hinders their applications. In this work, 20 base pairs long dsDNA fragments [(dCdG)20-65 %] composed 65 % dCdG and 35 dAdT nucleotides were tethered via a thiol to the surface gold electrode. The self-assembled (dCdG)20-65 monolayer was immersed in solutions containing ectoine, compatible solute. Electrochemical results showed these monolayers stable for one month. situ IR spectroscopy indicated ectoine interacts weakly with phosphate-ribose backbone, dehydrating phosphate groups stabilizing A-DNA conformation. This structural reorganization led reorientation nucleic acid local disruption double-helix structure. However, conformation orientation fragment ?0.4<E<0.3 potential range. As direct interaction between dsDNA, enzymatic reaction exonuclease VII hydrolyzing ester bond ssDNA, blocked. We show addition solute electrolyte solution stabilized structure despite rearrangements.