Luminescent lanthanide molecular materials as potential probes for the recognition of toxic and biologically important cations

Biologically relevant metal ions play a critical role in environmental and biological systems and are indispensable in various vital biochemical processes. Concomitantly, toxic metal ions are dangerous for humans and aquatic life when present in excess of permissible limits. Therefore, the sensitive and selective detection of these metal ions is of paramount importance. Due to their remarkable photophysical properties, luminescent probes derived from lanthanide molecular materials have recently provided an excellent platform for the detection of a wide range of toxic and biologically important metal species. This review focuses on the latest developments in lanthanide-based luminescent molecular probes, including lanthanide coordination complexes and lanthanide coordination polymers, that have been utilized for the detection of toxic metal ions. Emphasis is given to describing the general design features and range of mechanisms by which such sensors are able to elicit a luminescent response upon exposure to an analyte.