A novel terephthalaldehyde based turn-on fluorescent chemosensor for Cu and its application in imaging of living cells.

A new terephthaldehyde-based chemosensor 1 bearing an aminophenol recognition unit has been synthesized and applied to the fluorescent sensing of metal ions. Molecular system 1 acts as a highly selective and sensitive fluorescence turn-on sensor for Cu. The sensing mechanism has been explored. It is proposed that Cu binds with the imine and hydroxyl moiety of 1 in 1 : 2 binding stoichiometry, thereby enhancing the fluorescence at 386 nm. The detection limit and association constant (K) of 1 with Cu were found to be 0.62 μM and 6.67 × 10 M, respectively. Chemosensor 1 has shown excellent specificity towards Cu and has been successfully applied to the determination of Cu in live L929 cells.