A new sensor based on thieno[2,3-b]quinoline for the detection of In , Fe and F by different fluorescence behaviour.

Based on thieno[2,3-b]quinoline-2-carbohydrazide and salicylaldehyde, a novel fluorescent probe (L) was designed and synthesized. L could be used as a multifunctional sensor to sequentially detect In and Fe through fluorescence enhancement and fluorescence quenching in DMF/H O buffer solutions. At the same time, L had good anti-interference ability, which could still detect In and Fe well in the presence of other metal ions. For F , it could be detected by enhancing the fluorescence change caused by the introduction of Al . When other anions were present, the detection of F would not be interfered. The detection limits of In , Fe and F were 1.16 × 10  M, 2.03 × 10  M and 7.98 × 10  M, respectively. The complexation model and sensing mechanism between L and In , Fe and F were confirmed by calculating structural optimization and energy optimization using Gaussian 09 software.