Fluorimetric Chemosensors Combined with Familiar CSPT Devices for the Selective Detection of Mercury(II) Ions

Fluorimetric and Computer Screen Photoassisted Technique (CSPT) studies on the binding properties of three coumarin pendant arm derivatives of mixed aza-thioether macrocyclic ligands (L1-L3), incorporated into PVC plasticized polymeric membranes, towards a number of different metal cations were carried out. An enhanced selectivity of the ligands towards Hg2+ion was detected. In particular, the DOS plasticized membrane containing L3 and tetrakis(p-chlorophenyl)borate, TpClPB-, as lipophilic anionic additive, displayed a strong fluorescence activation by Hg2+over the wide concentration range of 10-7to 10-3M. The influence of the ratio among ligand and lipophilic additive on the membrane performance was tested. In addition, the CSPT measurements showed that L3 possesses a unique selectivity towards Hg2+ion with respect to several common diverse cations. Moreover CSPT technique permits to perform the fast and low cost monitoring of mercury (II) ions, by application of familiar devices and a chemometric approach.