Interactions of the DNA Nanostructure with Silane-Based Self-Assembled Monolayers

We show that the interactions with surfaces have a significant effect on the morphological outcome of deposited DNA nanostructures. We have modified silicon oxide surface with single and mixed self-assembled monolayers (SAMs). Amine-terminated silane was mixed with alkyl chlorosilanes of different chain lengths (C₁₈, C₆, and C₄) for SAM preparation to modulate the polarity and therefore wettability of the surface. We deposited DNA nanostructures onto these SAM-modified surfaces. Increasing the hydrophobicity of the surface increases the density of the deposited DNA nanostructure but at the cost of severe structural deformation. On the other hand, the number density of nondeformed DNA nanostructure initially increases and then decreases with increasing hydrophobicity of the surface.