Urea/thiourea-based chromofluorogenic chemosensors for metal ions and anions

Abstract

Urea and thiourea-based compounds contain nucleophilic heteroatoms such as O, S and N, allowing to establish intra- and intermolecular hydrogen bonding and coordinate bonding. Because of this fascinating property, significant research has been performed to develop urea and thiourea containing chromofluorogenic derivatives for the recognition and detection of many environmental and biological contaminants, even when present in traces. This review summarized the recently reported urea and thiourea-based small molecular chromofluorogenic chemosensors utilized for detecting diverse metal ions and anions, such as Ag+, Cu2+, Zn2+, Hg2+, Fe3+, F-, ClO-, CN-, AcO-, PO42-, and SO42-. The detection mechanisms, recognition modes, analytical innovations and potential applications in real samples of the reviewed chemosensors are discussed.