A benzothiazole containing CHEF based fluorescence turn-ON sensor for Zn2+ and Cd2+ and subsequent sensing of H2PO4- and P4O74- in physiological pH

A benzothiazole functionalized chemosensor L-1, exhibited colorimetric as well as fluorometric response to Zn2+ ion at physiological pH based on CHEF process. Selective naked eye detection of Zn2+ ion over most of the biologically important cations was also demonstrated. Sensing of biologically hazardous cadmium ion was also possible with L-1. Further, both the zinc and cadmium ensembles of L-1 were found to respond P4O74- and H2PO4- anion among other important biological anions and nucleotides via fluorescence quenching. Chemosensor L1, was also found to be reversible and recyclable toward Zn2+ and pyrophosphate ions over more than six cycles and responds to a INHIBIT logic gate. NMR titration and theoretical calculations were also conducted to understand the sensing behavior of L-1. (C) 2014 Elsevier B.V. All rights reserved.