基于水解活性的Zn2+荧光探针

合成了一种新颖的锌离子荧光探针N’(2-羟基苄基)-4-(2-羟基苯亚甲基胺)-苯甲酰肼(HHB),该探针本身的荧光较弱,但当它与Zn²⁺配位时荧光增强,在475 nm处产生一较宽的发射光谱,量子产率f=0.59 (λ_ex=370 nm)。该化合物对Zn²⁺具有良好的选择性能,环境生物体系中大量存在的碱金属和碱土金属离子K⁺,Na⁺,Mg²⁺和Ca²⁺以及过渡金属离子Mn²⁺,Co²⁺,Ni²⁺ 和 Cu²⁺ 等对Zn²⁺的检测没有明显影响。在生命体系的pH值范围(6.8~7.7),配合物HHB显示出对Zn²⁺检测较高的灵敏度。作为比较文中还研究了HHB水解的主要产物4-氨基苄腙-水杨醛(HB)对Zn²⁺的识别与传感性能。

Hydrolysis-activated Fluorophore System as a Molecular Sensor for Selective Detection of Zn2+

A new selective Zn2+ fluorescent sensor, N'-(2-hydroxybenzylidene)-4-(2-hydroxy-benzylidene-amino) benzohydrazide (HHB), was synthesized. With the harbored 2-hydroxybenzylidene group, HHB exhibits an emission band centered at 475 nm with high quantum yield (f= 0.59) upon the addition of zinc ions. It features excellent fluorescence enhancement and provides favorable sensitivity for Zn2+ detection under the biological pH window of 6.8~7.7, and high selectivity for Zn2+ over biologically relevant alkali metals, alkaline earth metals and some of the first row transition metal. It works through the metal-assisted hydrolysis mechanism, and the hydrolysis residue sensor HB, salicylaldehyde-4-aminobenzoylhydrazone, was also investigated for comparison.