Recent developments in fluorescent sensors for trace-level determination of toxic-metal ions

The literature on the use of fluorescent sensors for the trace-level determination of toxic cations is highly significant. Among different analytical methods, fluorescence is the most attractive due to its robustness, high sensitivity, selectivity, rapidity, ease of measurement and non-destructive methodology. Here, we illustrate different fluorescent probes developed for detection and estimation of toxic cations, including their molecular structure, sensing mechanism, analytical figures of merit and their applications. We provide a critical survey of the fluorescent sensors of each toxic element (i.e. Hg, Ag, Cd, Cr, Pb, Tl, Co and Ni). A separate section contains the sensors that can detect several toxic elements simultaneously, so-called multi-element sensors. We briefly describe the merits and the demerits of the methods. Finally, we outline future prospects in this field. (C) 2011 Elsevier Ltd. All rights reserved.