Supramolecular FRET modulation by pseudorotaxane formation of a ditopic stilbazolium dye and carboxylato-pillar[5]arene

•The complexation of stilbazolium dyes with water soluble carboxylato-pillar[5]arene was investigated.•The first stilbazolium-based FRET system is described.•FRET modulation of the ditopic stilbazolium dyad upon complexation with carboxylato-pillar[5]arene was observed.•Intramolecular FRET modulation by supramolecular complexation was achieved.

In this paper we introduce a new approach towards the modulation of fluorescence resonance energy transfer (FRET). Two stilbazolium dyes (A, D) exhibiting opposite fluorescence responses upon complexation with anionic, water soluble carboxylato-pillar[5]arene (WP5) were covalently linked via click chemistry, yielding a FRET-capable ditopic indicator (G). The pseudorotaxane formation of G with WP5 in pure water induced fluorescence enhancement combined with the modulation of the FRET process due to the interaction of the macrocycle with the two fluorophore units.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide