A novel isatin-based fluorescent chemosensor: Synthesis and recognition behaviour towards fe (III) and PPi in aqueous solution and living cells

In this paper, we have designed and synthesized a novel isatin-based Schiff base derivative L as a fluorescence probe for the relay recognition of Fe3+ and PPi in aqueous and live cells. L exhibited a highly selective and sensitive fluorescence quenching for Fe3+ ions through a 1:1 stoichiometry. The decomplexation of L-Fe3+ by PPi led to the liberation of the fluorescent ligand L and thus the fluorescence was switched on. The detection limits of L for Fe3+ and L-Fe3+ for PPi were estimated to be 1.37 x 10(-8) M and 4.21 x 10(-8) M, respectively. The low cytotoxicity and good cell-membrane permeability of L and L-Fe3+ complex makes them capable of Fe3+ and PPi imaging in living Hep G2 cells. (C) 2019 Elsevier Ltd. All rights reserved.