对Fe3+和草酸具有荧光“关-开”功能的喹啉衍生物

Quinoline derivative with fluorescent ‘off-on’ function for Fe3 and oxalic acid

摘要:

通过8-羟基喹啉-2-甲醛与水杨酰肼的缩合反应，合成了一种喹啉席夫碱衍生物荧光分子探针(L)。经FT-IR、1H NMR、13C NMR、ESI-MS表征，确定了探针L的分子结构。利用吸收和荧光光谱研究了探针L的识别性能。在DMSO溶液中，探针L与Fe3+能够形成1:1型配合物L-Fe，表观结合常数为4.6 × 104 L/mol。利用该配合物的形成导致的探针荧光猝灭，能够在常见金属离子中高选择性识别Fe3+，检出限为6.8 × 10-8 mol/L。进一步以L-Fe复合物为探针，实现了对草酸的高选择性荧光增强识别，检出限为1.3 × 10-7 mol/L。该方法可用于蔬菜中草酸的检测。

Abstract:

A fluorescent molecular probe (L) based quinoline schiff base was synthesized by the condensation reaction of 8-hydroxyquinoline-2-carboxaldehyde and salicylhydrazide. The molecular structure of the probe L was determined by FT-IR, 1H NMR, 13C NMR and ESI-MS. The recognition performance of probe L was studied by absorption and fluorescence spectra in DMSO solution. The probe L and Fe3+ could form a 1: 1 complex L-Fe, which binding constant is 4.6*104 L/mol. Through the quenching of probe fluorescence caused by the formation of the above complexes, Fe3+ could be selectively recognized in common metal ions, and the detection limit is 6.8* 10-8 mol/L. Furthermore, the L-Fe complex was used as a probe to achieve highly selective fluorescence enhanced recognition of oxalic acid, and the detection limit is 1.3*10-7 mol/L. This method could be used to detect oxalic acid in vegetables samples.