Recognition-mediated light-up of thiazole orange with cucurbit[8]uril: exchange and release by chemical stimuli

J Phys Chem B. 2012 Jan 12;116(1):130-5. doi: 10.1021/jp210432t. Epub 2011 Dec 19.

Abstract

This article reports a convenient supramolecular strategy to construct fluorescent photoswitchable molecular assemblies between a macrocyclic host, cucurbit[8]uril (CB8), and a fluorogenic dye, thiazole orange (TO). The interaction mechanism and the stable stoichiometric host-guest arrangements have been claimed on the basis of the optical absorption, steady-state and time-resolved fluorescence lifetime and anisotropy measurements, and also the geometry optimization studies. The CB8 recognized TO in its 2:2 stoichiometry exhibited spectacular fluorescence enhancement of the order of 1700 fold, which is the largest directly determined value so far reported for a dye in an organic macrocyclic system. This prospective 2CB8:2TO assembly responded to selected chemical stimuli such as metal ions, adamantylamine, and tryptophan, providing different dissociation mechanisms and demonstrating a controlled exchange and release action desired with such noncovalently linked assemblies. Positively, considering the aqueous solubility and biocompatibility of the host-guest constituents, this methodology can evolve into a general approach to deliver and operate intracellularly functional molecular components under chemical/thermal/optical trigger control, especially for therapeutic applications.

MeSH terms

  • Amantadine / chemistry
  • Benzothiazoles / chemistry*
  • Bridged-Ring Compounds / chemistry*
  • Imidazoles / chemistry*
  • Metals / chemistry
  • Quinolines / chemistry*
  • Spectrometry, Fluorescence
  • Tryptophan / chemistry

Substances

  • Benzothiazoles
  • Bridged-Ring Compounds
  • Imidazoles
  • Metals
  • Quinolines
  • cucurbit(8)uril
  • thiazole orange
  • Tryptophan
  • Amantadine