Blunt-End Driven Re-entrant Ordering in Quasi Two-Dimensional Dispersions of Spherical DNA Brushes

Autor(en)

Ivany Romero-Sanchez, Ilian Pihlajamaa, Natasa Adžić, Laura E. Castellano, Emmanuel Stiakakis, Christos N. Likos, Marco Laurati

Abstrakt

We investigate the effects of crowding on the conformations and assembly of confined, highly charged, and thick polyelectrolyte brushes in the osmotic regime. Particle tracking experiments on increasingly dense suspensions of colloids coated with ultralong double-stranded DNA (dsDNA) fragments reveal nonmonotonic particle shrinking, aggregation, and re-entrant ordering. Theory and simulations show that aggregation and re-entrant ordering arise from the combined effect of shrinking, which is induced by the osmotic pressure exerted by the counterions absorbed in neighbor brushes and of a short-range attractive interaction competing with electrostatic repulsion. An unconventional mechanism gives origin to the short-range attraction: blunt-end interactions between stretched dsDNA fragments of neighboring brushes, which become sufficiently intense for dense and packed brushes. The attraction can be tuned by inducing free-end backfolding through the addition of monovalent salt. Our results show that base stacking is a mode parallel to hybridization to steer colloidal assembly in which attractions can be fine-tuned through salinity and, potentially, grafting density and temperature.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie

Externe Organisation(en)

Università degli Studi di Firenze, Universidad de Guanajuato, Eindhoven University of Technology, Universität Wien, Forschungszentrum Jülich

Journal

ACS Nano

Band

16

Seiten

2133–2146

Anzahl der Seiten

14

ISSN

1936-0851

DOI

https://doi.org/10.1021/acsnano.1c07799

Publikationsdatum

2021

Peer-reviewed

Ja

ÖFOS 2012

103015 Kondensierte Materie

Schlagwörter

ASJC Scopus Sachgebiete

Allgemeine Materialwissenschaften, Allgemeiner Maschinenbau, Allgemeine Physik und Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/eed47932-a5c0-4b76-956a-d8a12fd08c2e