title: Contraction and Expansion of Stimuli-Responsive DNA Bonds in Flexible Colloidal Crystals.
abstract: DNA surface ligands can be used as programmable "bonds" to control the arrangement of nanoparticles into crystalline superlattices. Here, we study the intrinsic responsiveness of these DNA bonds to changes in local dielectric constant (εr) as a new approach to dynamically modulate superlattice structure. Remarkably, ethanol (EtOH) addition can be used to controllably tune DNA bond length from 16 to 3 nm and to increase bond stability by >40 °C, while retaining long-range order and crystal habit. Interestingly, we find that these structural changes, which involve the expansion and contraction of crystals by up to 75% in volume, occur in a cooperative fashion once a critical percentage of EtOH is reached. These results provide a facile and robust approach to create stimuli-responsive lattices, to access high volume fractions, and to improve thermal stability.
authors.affiliation: Department of Chemistry, ‡International Institute for Nanotechnology, §Department of Chemical and Biological Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Jarad A
authors.initials: JA
authors.lastname: Mason
authors.affiliation: Department of Chemistry, ‡International Institute for Nanotechnology, §Department of Chemical and Biological Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Christine R
authors.initials: CR
authors.lastname: Laramy
authors.affiliation: Department of Chemistry, ‡International Institute for Nanotechnology, §Department of Chemical and Biological Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Cheng-Tsung
authors.initials: CT
authors.lastname: Lai
authors.affiliation: Department of Chemistry, ‡International Institute for Nanotechnology, §Department of Chemical and Biological Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Matthew N
authors.initials: MN
authors.lastname: O'Brien
authors.affiliation: Department of Chemistry, ‡International Institute for Nanotechnology, §Department of Chemical and Biological Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Qing-Yuan
authors.initials: QY
authors.lastname: Lin
authors.affiliation: Department of Chemistry, ‡International Institute for Nanotechnology, §Department of Chemical and Biological Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Vinayak P
authors.initials: VP
authors.lastname: Dravid
authors.affiliation: Department of Chemistry, ‡International Institute for Nanotechnology, §Department of Chemical and Biological Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: George C
authors.initials: GC
authors.lastname: Schatz
authors.affiliation: Department of Chemistry, ‡International Institute for Nanotechnology, §Department of Chemical and Biological Engineering, and ∥Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Chad A
authors.initials: CA
authors.lastname: Mirkin