Superlattices assembled through shape-induced directional binding

Abstract

Organization of spherical particles into lattices is typically driven by packing considerations. Although the addition of directional binding can significantly broaden structural diversity, nanoscale implementation remains challenging. Here we investigate the assembly of clusters and lattices in which anisotropic polyhedral blocks coordinate isotropic spherical nanoparticles via shape-induced directional interactions facilitated by DNA recognition. We show that these polyhedral blocks—cubes and octahedrons—when mixed with spheres, promote the assembly of clusters with architecture determined by polyhedron symmetry. Moreover, three-dimensional binary superlattices are formed when DNA shells accommodate the shape disparity between nanoparticle interfaces. The crystallographic symmetry of assembled lattices is determined by the spatial symmetry of the block's facets, while structural order depends on DNA-tuned interactions and particle size ratio. The presented lattice assembly strategy, exploiting shape for defining the global structure and DNA-mediation locally, opens novel possibilities for by-design fabrication of binary lattices.

Limiting the valence: advancements and new perspectives on patchy colloids, soft functionalized nanoparticles and biomolecules

“…23 A similar strategy, which employs DNA-grafted polyhedral blocks to add directional binding, has been recently proposed. 160 However, valency can also be enforced in systems made of uniformly grafted DNA-CC, provided that the DNA strands can diffuse over the surface, 240 as suggested by Angioletti-Uberti et al 241 The basic idea revolves around grafting additional nonbinding DNA strands onto the particle surface: thanks to the many-body nature of the interaction between DNA-CC, the resulting particle valence is controlled by the interplay between the non-specific repulsion, which depends on the strand length, temperature and salt concentration, and the attraction due to DNA hybridisation. Coarse-grained simulations show that, in contrast to DNA-CC with immobile DNA linkers, these limitedvalence DNA-CC can self-assemble into open structures.…”

“…(i) anisotropic polyhedral blocks and spheres, for instance, assemble into complex superlattices that can be tuned by the choice of the DNA shells and the particle size mismatch between the two components of the mixtures; 160 (ii) rigid tetrahedral DNA origami cages and spherical nano-particles can form a family of lattices based on the diamond motif. 162 When focusing on one-component systems of anisotropic particles decorated with anisotropic bonding patterns, most of the results accumulated so far in the literature deal with Janus-like nonspherical entities -mainly elongated shapes carrying one or at most two patches -assembling into a vast variety of fiber-like structures with diverse applications.…”

“…Binary mixtures of different shapes with mutual attraction induced by isotropically distributed, complementary DNA strands can already exhibit a wide range of exotic extended architectures [160][161][162] (see also Section 3.2):…”

Optical properties of anisotropic 3D nanoparticles arrays

“…Self-assembly of 3D systems of noble metal nanoparticles can be achieved using DNA linkers as a scaffolding [1][2][3]. By changing the number of DNA-base pairs, superlattice engineering of different crystalline structures [4] is possible as well as directional crystallization [5,6]. The many applications derived from DNA superlattice engineering include the assembly of superstructures for biological delivery [7], biosensors [8], tuning of the plasmonic response of superlattices [9,10], ordering of Au nanoparticles in one-dimensional arrays [11,12], among others.…”

Mighty linkers

“…The last few months have witnessed further developments in the rational design of ordered nanoparticle assemblies. Both Chad Mirkin and Oleg Gang, and their respective collaborators, have recently shown that nanoparticles with vastly distinct shape and/or moderately different size can be co-crystallized (for example, octahedra and spheres of similar size 8 ; or cubes and disks of different diameter 9 ). As noted by Jean-Philippe Sobczak and Hendrik Dietz in a News & Views article 10 , to achieve large co-crystals with long-range order, one can either use nanoparticles with a high degree of shape complementarity together with stiffer (double-stranded) DNA linkers, or more flexible (singlestranded) linkers that compensate for a low degree of structural complementarity between nanoparticles.…”