Fluorogenic ratiometric dipodal optode containing imine-amide linkages: Exploiting subtle thorium (IV) ion sensing

The (13E, 19E)-N1', N3'-bis[4-(diethylamino)-2-hydroxybenzylidene] malonohydrazide (L) has been developed for the detection of Th4+ ions using dual channel signalling system. The UV-vis absorbance and fluorescence spectroscopic data revealed the formation of L-Th4+ complex in 1: 1 equilibrium. The density functional theory (DFT) also confirms the optimum binding cavity for the recognition of metal ion. The binding constant computed from different mathematical models for an assembly of L-Th4+. The detection limit of L for Th4+ recognition is to a concentration down to 0.1 mu M (0.023 mu g g (1)). The present sensing system is also successfully applied for the detection of Th4+ ion present in soil near nuclear atomic plants. (C) 2014 Elsevier B.V. All rights reserved.