DNA adsorption at liquid/solid interfaces

TL;DR

This study investigates how double-stranded DNA molecules adsorb onto a positively-charged silicon surface using x-ray reflectivity, revealing high surface coverage and potential 2D nematic ordering of the DNA layer.

Contribution

It provides detailed insights into DNA adsorption mechanisms on charged surfaces, highlighting the embedding and deformation of DNA within a soft monolayer.

Findings

High surface coverage of DNA on the substrate

DNA embeds into and deforms the monolayer

Potential for 2D nematic ordering of adsorbed DNA

Abstract

DNA adsorption on solid or liquid surfaces is a topic of broad fundamental and applied interest. Here we study by x-ray reflectivity the adsorption of monodisperse double-stranded DNA molecules a positively-charged surface, obtained through chemical grafting of a homogeneous organicmonomolecular layer of N-(2-aminoethyl) dodecanamide on an oxide-free monocrystalline Si(111) wafer. The adsorbed dsDNA is found to embed into the soft monolayer which is deformed in the process. The surface coverage is very high and this adsorbed layer is expected to display 2D nematic ordering.