Cucurbit[8]uril-mediated triphenylamine coumarin derivative cascade assembly for NIR targeted cell imaging

Abstract

A coumarin-modified tris[4-(4-pyridyl)phenyl]amine compound was encapsulated in the cavity of cucurbit[8]uril with a 2 : 3 stoichiometric ratio, which not only effectively enhances the guest fluorescence emission with a hypsochromic shift of about 51 nm by macrocycle confinement, but also allows cascade assembly with β-cyclodextrin-grafted hyaluronic acid (HACD) to construct a ternary supramolecular network. Furthermore, doping of sulfo-cyanine 5 into the β-cyclodextrin cavity of HACD through host–guest interaction achieved a high efficiency Förster resonance energy transfer system from the supramolecular network to dyes, which was successfully applied to near-infrared mitochondria-targeted imaging in HeLa cells.