Abstract

A Schiff-base type fluorescent sensor (PLB3) was synthesized by nucleophilic addition-elimination between 2-hydroxy-1-naphthaldehyde and 5-chloro-2-aminopyridine. Single crystal X-ray diffraction analysis demonstrated keto-amine isomer was predominantly adopted. 8-Fold fluorescence-enhanced recognition for detecting Zn²⁺ was chelation enhanced fluoresce (CHEF) mechanism. Also, PLB3 could distinguish well Zn²⁺ from analogue Cd²⁺. Job’s plot fluorescence titration and UV–Vis titration revealed the 1:1 stoichiometry between Zn²⁺ and PLB3. The association constant (K_a) and limit of detection (LOD) were 5.14 × 10⁷ M⁻¹ and 0.33 μM, respectively. The excellent selective and sensitive properties urge PLB3 to detect the trace amounts of Zn²⁺ in the environmental systems.

摘要

通过 2-hydroxy-1-naphthaldehyde 和 5-chloro-2-aminopyridine 之间的亲核加成-消除合成了席夫碱型荧光传感器 (PLB3)。单晶X射线衍射分析表明主要采用酮胺异构体。^{Zn 2+}检测的8倍荧光增强识别是螯合增强荧光(CHEF)机制。此外，PLB3 可以很好地区分 Zn ²⁺与类似物 Cd ²⁺。^{Job's plot 荧光滴定和 UV-Vis 滴定揭示了 Zn 2+}和 PLB3之间的 1:1 化学计量。缔合常数 ( K _a ) 和检测限 (LOD) 分别为 5.14 × 10 ⁷ M ⁻¹和 0.33  μM，分别。出色的选择性和灵敏性促使 PLB3 检测环境系统中的微量 Zn ^{2+ 。}