Recent Advances in Stimuli-Responsive Luminescent Supramolecular Lanthanide-Based Metallogels

Abstract

The use of lanthanide-based metallogels presents a promising approach for the engineering of stimuli-responsive gel materials. Stimuli-responsive luminescent materials based on lanthanides have promising applications in bio-applications and optical encoding. Synthetic supramolecular metallogels typically become kinetically trapped and usually do not exhibit time-variable changes in their material properties. However, such supramolecular metallogels can switch between gel to sol when subjected to different external physical and chemical stimuli. This is because weak noncovalent interactions hold together the gel structure and are also influenced by the coordination dynamics of the metal-ligand bond. This review summarizes recent research progress on stimuli-responsive supramolecular lanthanide-based luminescent metallogels. Chemical, physical, and multiple stimuli-responsiveness of the metallogels are discussed elaborately based on the external stimulus sources. Finally, the latest challenges and opportunities for developing novel metallogels that respond to stimuli are discussed.