Reversible end-to-end assembly and disassembly of gold nanorods based on pH-responsive host-guest interaction

Abstract

The reversible end-to-end assembly and disassembly of gold nanorods (GNRs) were efficiently realized by utilizing the pH-responsive host-guest interaction. The guest compound, containing a 4,4'-bipyridine unit and a disulfide group, was synthesized, and could form the 2:1 inclusion compounds with cucurbit[8]uril (CB[8]) host molecules quickly in aqueous solution. Due to the fact that the inclusion compounds could be destroyed and re-formed by adjusting the solution pH, the terminal-modified GNRs could realize the reversible end-to-end assembly and disassembly. The end-to-end assembly and disassembly of GNRs were well characterized by UV–Vis spectra and TEM images. This method, employing supramolecular host-guest interaction to control the reversible linear assembly and disassembly of GNRs, may provide a new idea for the design of smart organic-inorganic hybrid materials.