Surfactant assemblies encapsulating fluorescent probes as selective and discriminative sensors for metal ions

Abstract

Detecting and analyzing metal ions in the environment have drawn great attention due to the hazardous metal pollutions exposed to human being and creatures. Fluorescent sensors for metal ions have been a hot research spot for a few decades as they possess advantages in terms of sensitivity, selectivity, non-invasive detecting, easy operation, etc. Among various types of fluorescent sensors for metal ions, fluorescent ensembles based on fluorophores/surfactant assemblies represent a very specific type and have attracted increasing interests. Surfactant assemblies are amphiphilic and can provide hydrophobic core for encapsulating fluorophores to detect metal ions in aqueous media. Moreover, the dynamic balance feature enables surfactant assemblies to easily modulate the fluorescence properties of encapsulated fluorophores and the sensing behaviors of such ensembles. A great number of fluorescent ensembles based on surfactant assemblies encapsulating fluorophores have been developed as fluorescent sensors for metal ions, which can be used for selective sensing, detecting multiple metal ions, cross-reactive responding for discriminating more metal ions. The present review introduces the development of each type of these fluorescent ensemble-based sensors, particularly presenting the strategies for obtaining these sensors and methods for adjusting their sensing behaviors. This may help to develop more efficient and powerful fluorescent sensors for metal ions.