title: Directional emission from dye-functionalized plasmonic DNA superlattice microcavities.
abstract: Three-dimensional plasmonic superlattice microcavities, made from programmable atom equivalents comprising gold nanoparticles functionalized with DNA, are used as a testbed to study directional light emission. DNA-guided nanoparticle colloidal crystallization allows for the formation of micrometer-scale single-crystal body-centered cubic gold nanoparticle superlattices, with dye molecules coupled to the DNA strands that link the particles together, in the form of a rhombic dodecahedron. Encapsulation in silica allows one to create robust architectures with the plasmonically active particles and dye molecules fixed in space. At the micrometer scale, the anisotropic rhombic dodecahedron crystal habit couples with photonic modes to give directional light emission. At the nanoscale, the interaction between the dye dipoles and surface plasmons can be finely tuned by coupling the dye molecules to specific sites of the DNA particle-linker strands, thereby modulating dye-nanoparticle distance (three different positions are studied). The ability to control dye position with subnanometer precision allows one to systematically tune plasmon-excition interaction strength and decay lifetime, the results of which have been supported by electrodynamics calculations that span length scales from nanometers to micrometers. The unique ability to control surface plasmon/exciton interactions within such superlattice microcavities will catalyze studies involving quantum optics, plasmon laser physics, strong coupling, and nonlinear phenomena.
authors.affiliation: Department of Chemistry, Northwestern University, Evanston, IL 60208.|International Institute for Nanotechnology, Northwestern University, Evanston, IL 60208.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Park
authors.affiliation: International Institute for Nanotechnology, Northwestern University, Evanston, IL 60208.|Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208.
authors.forename: Jessie C
authors.initials: JC
authors.lastname: Ku
authors.affiliation: International Institute for Nanotechnology, Northwestern University, Evanston, IL 60208.|Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208.
authors.forename: Lin
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Chemistry, Northwestern University, Evanston, IL 60208.
authors.forename: Clotilde M
authors.initials: CM
authors.lastname: Lethiec
authors.affiliation: Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208.
authors.forename: Nathaniel P
authors.initials: NP
authors.lastname: Stern
authors.affiliation: Department of Chemistry, Northwestern University, Evanston, IL 60208; g-schatz@northwestern.edu chadnano@northwestern.edu.|International Institute for Nanotechnology, Northwestern University, Evanston, IL 60208.
authors.forename: George C
authors.initials: GC
authors.lastname: Schatz
authors.affiliation: Department of Chemistry, Northwestern University, Evanston, IL 60208; g-schatz@northwestern.edu chadnano@northwestern.edu.|International Institute for Nanotechnology, Northwestern University, Evanston, IL 60208.|Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208.
authors.forename: Chad A
authors.initials: CA
authors.lastname: Mirkin
mesh_terms: D004396:Coloring Agents; D003198:Computer Simulation; D003460:Crystallization; D004247:DNA / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D015591:Microspectrophotometry; D008958:Models, Molecular; D036103:Nanotechnology; D055620:Optical Phenomena; D012822:Silicon Dioxide
chemical_list: D004396:Coloring Agents; D006046:Gold; D012822:Silicon Dioxide; D004247:DNA
keywords: DNA programmable assembly; anisotropic 3D microcavity; directional emission; fluorescence enhancement; nanoparticle surface plasmon