Interactions of DNA oligomers with
two categories of semiconducting
nanostructureschalcogenide quantum dots (QDs) and boron nitride
nanotubes (BNNTs)owing to their widespread presence in bio-inspired
processes are investigated using the first-principles density functional
theory and continuum solvent model. The chalcogenide QDs interact
strongly at their metal centers featuring electrostatic interaction
with DNA oligomers at oxygen or nitrogen site, while BNNTs form covalent
bonds with DNA oligomers at multiple surface sites. It is found that
the different bonding nature leads to distinctly different response
to the aqueous environment; the presence of solvent drastically reduces
the binding strength of nucleobases with the QDs due to the strong
electrostatic screening. This is not the case with BNNTs for which
the covalent bonding is barely affected by the solvent. This study
thus clearly shows how a solvent medium influences chemical interactions
providing guidance for technological applications of bioconjugated
systems