Near-infrared photoswitching of cyclodextrin-guest complexes using lanthanide-doped LiYF₄ upconversion nanoparticles

This communication reports a new type of supramolecular cyclodextrin-guest complexes using cyclodextrin coated upconversion nanoparticles as hosts and monovalent and divalent azobenzenes and arylazopyrazoles as guests. A potentially biocompatible photocontrol of the interaction by isomerization of the azobenzene or arylazopyrazole was achieved by laser irradiation at 980 nm and a very low light intensity of 0.22 W cm^-2.