Azobenzene DNA intercalator/cyclodextrin pseudo-rotaxane: from photoswitchable chirality and fluorescence to DNA melting control

Pseudo-rotaxanes are reversibly interlocked molecules with at least one linear molecule threaded into a macrocycle and, contrary to rotaxanes, an advantageous ability to be dissociated. Cyclodextrins constitute attracting macrocyclic host entities to build such dynamic structures for their oligosaccharide nature, conic shape, amphiphilic character and biocompatibility. Here we show that using an azobenzene DNA intercalator as a guest allows to build a pseudo-rotaxane combining several remarkable properties, including light-controlled assembly/disassembly, photoreversible chirality and fluorescence, as well as the capability to affect the melting temperature of double-stranded DNA through intercalator host-guest complexation.