Pyridoxal derived chemosensor for chromogenic sensing of Cu2+ and fluorogenic sensing of Fe3+ in semi-aqueous medium

An easy-to-prepare chemosensor L was developed by condensation of pyridoxal with 1,8-diaminonaphthalene. In DMSO:H2O (1:1, v/v), sensor L displayed a highly selective and sensitive response towards Cu2+via perceptible color and UV-vis absorbance changes among the other tested metal ions. However, the fluorescence of L is selectively quenched in the presence of both Fe3+ and Cu2+. With a micromolar detection limit and non-interference from other co-existing metal ions, this sensor can be applied over a wide pH range for the detection of Fe3+ and Cu2+. In addition, the cytotoxicity and fluorescence changes of L within live HeLa cells were examined in the absence and presence of Cu2+.