Shape-Dependent Oriented Trapping and Scaffolding of Plasmonic Nanoparticles by Topological Defects for Self-Assembly of Colloidal Dimers in Liquid Crystals

• Published in: Nano letters Vol. 12; no. 2; pp. 955 - 963
• Main Authors: Senyuk, Bohdan, Evans, Julian S, Ackerman, Paul J, Lee, Taewoo, Manna, Pramit, Vigderman, Leonid, Zubarev, Eugene R, van de Lagemaat, Jao, Smalyukh, Ivan I
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 08.02.2012
• Subjects: Collective excitations (including excitons, polarons, plasmons and other charge-density excitations); Colloids; Colloids - chemical synthesis; Colloids - chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Crystal defects; Dimerization; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Liquid crystals; Liquid Crystals - chemistry; Microspheres; Nanoparticles; Nanoparticles - chemistry; Nanostructure; Particle Size; Physics; Plasmonics; Scaffolding; Self assembly; Surface and interface electron states; Surface Plasmon Resonance; Surface Properties; nanoscale self-assembly; liquid crystal elasticity; colloids; topological defects; optical trapping; Plasmonic nanoparticles; Gold; Topological defect; Uniform field; Boundary conditions; Nanoplasmonics; Liquid crystals; Nanoparticles; Microspheres; Optical trapping; Self-assembly; Anisotropy; Transition elements; Superstructure; Surface plasmon resonance; Arrays
• DOI: 10.1021/nl204030t
• ISSN: 1530-6984

We demonstrate scaffolding of plasmonic nanoparticles by topological defects induced by colloidal microspheres to match their surface boundary conditions with a uniform far-field alignment in a liquid crystal host. Displacing energetically costly liquid crystal regions of reduced order, anisotropic nanoparticles with concave or convex shapes not only stably localize in defects but also self-orient with respect to the microsphere surface. Using laser tweezers, we manipulate the ensuing nanoparticle-microsphere colloidal dimers, probing the strength of elastic binding and demonstrating self-assembly of hierarchical colloidal superstructures such as chains and arrays.