Get the lead out: The title fluorescence receptor exhibits a high affinity and selectivity for Pb(2+) over competing metal ions in water (see picture) with an overall emission change of approximately 8-fold at the emission maximum for Pb(2+). The fluorescence receptor can remove 96 % of 100 ppb Pb(2+) from human blood, and can be useful and effective for the selective and rapid removal of Pb(2+) in vivo.