Imine-functionalized thioether Zn(II) turn-on fluorescent sensor and its selective sequential logic operations with H2PO4-, DFT computation and live cell imaging

摘要

The diformyl thioether Schiff base (H2L) exhibits fluorescent sensing behaviour towards Zn2+ with a limit of detection (LOD) of 0.050 mu M, which is far below the WHO guideline (76 mu M) in drinking water. The formation of a 1 : 1 metal-to-ligand complex, [ZnL], has been ascertained by X-ray crystallography, Job's plot and mass spectra. The fluorogenic complex, [ZnL] (either in situ or a solution of the isolated complex) has shown selective ON-OFF emission toward H2PO4-. A two-input, one-output sequential INHIBIT logic circuit has been constructed from H2L, Zn2+ and H2PO4-. The practical applicability of H2L has been examined by the identification of Zn2+ and H2PO4- in the intracellular fluid of African monkey Vero cells.