title: Mobile linkers on DNA-coated colloids: valency without patches.
abstract: Colloids coated with single-stranded DNA (ssDNA) can bind selectively to other colloids coated with complementary ssDNA. The fact that DNA-coated colloids (DNACCs) can bind to specific partners opens the prospect of making colloidal "molecules." However, in order to design DNACC-based molecules, we must be able to control the valency of the colloids, i.e., the number of partners to which a given DNACC can bind. One obvious, but not very simple approach is to decorate the colloidal surface with patches of single-stranded DNA that selectively bind those on other colloids. Here we propose a design principle that exploits many-body effects to control the valency of otherwise isotropic colloids. Using a combination of theory and simulation, we show that we can tune the valency of colloids coated with mobile ssDNA, simply by tuning the nonspecific repulsion between the particles. Our simulations show that the resulting effective interactions lead to low-valency colloids self-assembling in peculiar open structures, very different from those observed in DNACCs with immobile DNA linkers.
authors.affiliation: Department of Physics, Humboldt University of Berlin, Newtonstrasse 15, 12489 Berlin, Germany.
authors.forename: Stefano
authors.initials: S
authors.lastname: Angioletti-Uberti
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, United Kingdom.
authors.forename: Patrick
authors.initials: P
authors.lastname: Varilly
authors.affiliation: Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, Code Postal 231, Campus Plaine, B-1050 Brussels, Belgium.
authors.forename: Bortolo M
authors.initials: BM
authors.lastname: Mognetti
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, United Kingdom.
authors.forename: Daan
authors.initials: D
authors.lastname: Frenkel
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D018076:DNA, Complementary / Q000737:chemistry* / Q000235:genetics; D004277:DNA, Single-Stranded / Q000737:chemistry* / Q000235:genetics; D008956:Models, Chemical; D013816:Thermodynamics
chemical_list: D003102:Colloids; D018076:DNA, Complementary; D004277:DNA, Single-Stranded