Macroscopic photonic single crystals via seeded growth of DNA-coated colloids

Abstract

Photonic crystals—a class of materials whose optical properties derive from their structure in addition to their composition—can be created by self-assembling particles whose sizes are comparable to the wavelengths of visible light. Proof-of-principle studies have shown that DNA can be used to guide the self-assembly of micrometer-sized colloidal particles into fully programmable crystal structures with photonic properties in the visible spectrum. However, the extremely temperature-sensitive kinetics of micrometer-sized DNA-functionalized particles has frustrated attempts to grow large, monodisperse crystals that are required for photonic metamaterial applications. Here we describe a robust two-step protocol for self-assembling single-domain crystals that contain millions of optical-scale DNA-functionalized particles: Monodisperse crystals are initially assembled in monodisperse droplets made by microfluidics, after which they are grown to macroscopic dimensions via seeded diffusion-limited growth. We demonstrate the generality of our approach by assembling different macroscopic single-domain photonic crystals with metamaterial properties, like structural coloration, that depend on the underlying crystal structure. By circumventing the fundamental kinetic traps intrinsic to crystallization of optical-scale DNA-coated colloids, we eliminate a key barrier to engineering photonic devices from DNA-programmed materials.

DNA-Coated Microspheres with Base Mismatches for Stepwise Programmed Assembly

“…DNA-coated colloids can be assembled into uniform crystalline structures, which can then serve as seeds for assembling other types of DNA-coated particles, leading to the formation of core−shell structures. Unlike a multistep reaction process, 41 for the efficient growth of intricate and hierarchical structures in a single step, we introduced encoding sequences with partial complementarity in the DNA brushes on the colloids. Through this approach, we demonstrated the programmed assembly of hierarchical structures in a stepwise manner.…”

Interplay of condensation and chromatin binding underlies BRD4 targeting

“…4A, B). The third outcome arises because the growth of the first condensates to form suppresses the nucleation of additional condensates elsewhere 47,48 , and subsequent coalescence is extremely slow. Leveraging the high spatiotemporal control over condensate initiation enabled by the Corelet system, we measured these three parameters of BRD4 FL nucleation before and after addition of JQ1 (1 μm, 90 min).…”

Lattice Model Results for Pattern Formation in a Mixture with Competing Interactions

“…Among the possible patterns, stripes or layers with different thicknesses often appear in one-component systems of particles [5,7,25], or in mixtures [20,[27][28][29][30]. Ordered thin stripes of alternating components can find various technological applications, such as in photonic crystals [31,32] or optoelectronic devices [33]. Fundamental knowledge concerning conditions that support the spontaneous formation of ordered stripes is important.…”