Reversible and multisensitive quantum dot gels

Functional fluorescent semiconductor quantum dot (QD) based gels prepared via immobilizing QDs in organic matrices have shown promising properties, but the compatibility of QDs and organic matrix is not good, and the interactions of the ligands on the surface of QDs with organic matrix are weak, which lead to poor dispersion of QDs in the formed gel and decrease of photoluminescence after gelation in some cases. In this work, we report a hyperbranched macromolecule that can not only act as an excellent ligand to stabilize QD but also act as a good gelator that can gel QD solution to form a reversible and multiresponsive fluorescent gel. This hyperbranched macromolecule-capped QD is stable, and the sol-gel switching can be easily realized via heating and ultrasonicating. Most important, the formed QD gel shows stronger fluorescence than that of the corresponding solution. This novel QD-hyperbranched macromolecule inorganic/organic hybrid network shows great promise in fields such as imaging, sensors, drug release, and nanoscience.