title: Reversible assembly and disassembly of receptor-decorated gold nanoparticles controlled by ion recognition.
abstract: The controlled assembly of randomly dispersed colloidal particles can provide access to materials with advanced optical and electronic properties while providing fundamental insights into self-assembly processes in nature and nanotechnology. Typically, self-assembled nanoparticles are prepared by exploiting electrostatic interactions, lithographic techniques, and covalently linked molecular scaffolds. This results in static morphologies that cannot be disassembled easily. On the other hand, having access to systems that can be assembled or disassembled in a controlled manner could allow for in-depth understanding of the nanoparticles as well as rational control over the morphology and fundamental properties of the resulting constructs. If the changes in aggregation are induced by a specific external chemical stimulus, it could also permit the development of new chemosensors. Here we demonstrate the reversible assembly and disassembly of gold nanoparticles achieved by modulating the noncovalent interactions between surface-bound calix[4]pyrroles and added bis-imidazolium cations. We also demonstrate the use of these nanoparticles in the selective sensing of anions.
authors.affiliation: Department of Chemistry, Istanbul Technical University, Maslak, 34469 Istanbul (Turkey); Department of Chemistry, The University of Texas at Austin, Austin, TX 78712-1224 (USA).
authors.forename: Abdullah
authors.initials: A
authors.lastname: Aydogan
authors.forename: Gawon
authors.initials: G
authors.lastname: Lee
authors.forename: Chang-Hee
authors.initials: CH
authors.lastname: Lee
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Sessler
keywords: anion sensors; calix[4]pyrroles; gold nanoparticles; reversible assembly-disassembly