“Turn-On” fluorescent chemosensor based on β-diketone for detecting Th4+ ions in Aqueous Solution and application in living cell imaging

A fluorescent sensor Hn based on β-diketone derivative for Th 4+ ions was designed and investigated, which showed high selectivity in the present of other metal ions even UO 2 2+ in CH 3 OH:H 2 O (v/v   =   2:8, pH   =   7.2) solution. Meanwhile, the binding mode of the sensor Hn with Th 4+ ions was found to be 1:1 with association constant of 2.46   ×   10 4   M −1 . And there was linear relationship between the fluorescent intensity of Hn -Th 4+ and the concentration of Th 4+ ions covering a range of 0.06   μM–1.0   μM and the detection limit was 0.0344   μM. At the same time, the interaction properties between the sensor Hn and Th 4+ ions and the fluorescent mechanism were investigated by IR, 1 HNMR and DFT. Most importantly, this fluorescent sensor was successfully utilized for the fluorescent imaging of Th 4+ ions in living cells.