title: Increasing the Morphological Stability of DNA-Templated Nanostructures with Surface Hydrophobicity.
abstract: DNA has been extensively used as a versatile template to assemble inorganic nanoparticles into complex architectures; thanks to its programmability, stability, and long persistence length. But the geometry of self-assembled nanostructures depends on a complex combination of attractive and repulsive forces that can override the shape of a molecular scaffold. In this report, an approach to increase the morphological stability of DNA-templated gold nanoparticle (AuNP) groupings against electrostatic interactions is demonstrated by introducing hydrophobicity on the particle surface. Using single nanostructure spectroscopy, the nanometer-scale distortions of 40 nm diameter AuNP dimers are compared with different hydrophilic, amphiphilic, neutral, and negatively charged surface chemistries, when modifying the local ionic strength. It is observed that, with most ligands, a majority of studied nanostructures deform freely from a stretched geometry to touching particles when increasing the salt concentration while hydrophobicity strongly limits the dimer distortions. Furthermore, an amphiphilic surface chemistry provides DNA-linked AuNP dimers with a high long-term stability against internal aggregation.
authors.affiliation: ESPCI ParisTech PSL Research University, CNRS, INSERM, Institut Langevin, 1 rue Jussieu, F-75005, Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Lermusiaux
authors.affiliation: ESPCI ParisTech PSL Research University, CNRS, INSERM, Institut Langevin, 1 rue Jussieu, F-75005, Paris, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Bidault
mesh_terms: D004247:DNA / Q000737:chemistry*; D004355:Drug Stability; D006046:Gold / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D053768:Metal Nanoparticles / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D058105:Polymerization; D011108:Polymers; D013499:Surface Properties
chemical_list: D011108:Polymers; D011092:Polyethylene Glycols; D006046:Gold; D004247:DNA
keywords: DNA nanotechnology; amphiphilic ligands; darkfield microscopy; nanostructures; self-assembly