Fluorescent supramolecular self-assembly gels and their application as sensors: A review

Low molecular weight gels (LMWGs) have been extensively studied and used in the context of supramolecular chemistry due to their ability to construct functional soft materials through noncovalent interactions. This class of soft materials can retain not only beneficial features of both solution and solid state, but also provide the ability to synergistically tune their properties through the combination of many influence factors such as temperature, gelator, and solvents. LMWGs have been widely applied in many fields as a result of their self-assembly structures, three-dimension network and large effective surface area. Among these LMWGs, fluorescent LMWGs have received more and more attention on accounts of their excellent photophysical properties, especially for the aggregation-induced emission behavior. The above advantages endow fluorescent LMWGs outstanding sensing ability with multiple detection approaches (solution, gel and xerogel state) and signaling modes (color, fluorescence and gel state change). This review focuses on the recent development of fluorescent supramolecular gels as sensors for applications in environmental and biological field, in which these fluorescent chemosensors can selectively detect specific metal ions, organic compounds or gases.