高选择性检测Hg2+的喹啉酮衍生物荧光探针的合成及应用

设计合成了一种以喹啉酮为荧光团，具有新型结构的荧光探针（E）-N-（4-甲基-2-氧代-1，2-二氢喹啉-7-基）-3-（3-苯基-1，2，4]三唑3，4-b]1，3，4]噻二唑-6-基）丙烯酰胺（MNT）.研究结果表明，MNT可通过不饱和酰胺键异构化后与Hg²⁺配位，从而产生显著的荧光猝灭.1，2，4-三唑3，4-b]-1，3，4-噻二唑缺电子的特征有助于提高猝灭效果的同时，能提供与Hg²⁺配位的杂原子.MNT探针对Hg²⁺具有高选择性、较高的量子产率和较强的抗干扰性，检测限为6.35×10^-8 mol/L，响应时间25 s.进一步研究发现，MNT在pH=4~13范围内均能特异性检测Hg²⁺.基于核磁滴定实验结果推测了该探针荧光检测Hg²⁺的机理，并由Job’s曲线确定了MNT与Hg²⁺之间的配位比为2：1.MNT在实际水样中的应用结果表明其可作为检测Hg²⁺的荧光探针.

Synthesis and Application of Quinolinone Derivative Fluorescent Probe for High Selective Detection of Hg2+

In order to well-directed fluorescence recognize and detect Hg²⁺, according to the coordination characteristics of Hg²⁺, a novel fluorescent probe (E)-N-(4-methyl-2-oxo-1,2-dihydroquinolin-7-yl)-3-(3-phenyl-1,2,4]triazolo3,4-b] 1,3,4]thiadiazol-6-yl)acrylamide(MNT) was designed and synthesized, which quinolinone block was used as fluorophore. The results showed that MNT could coordinate with Hg²⁺ after the isomerization of amide bond, therefore the fluorescence quenching was generated. 1,2,4-Triazole3,4-b]-1,3,4-thiadiazole had the characteristic of lacking electrons, which could improve the quenching effect and coordinate with Hg²⁺. The probe MNT had higher selectivity, higher quantum yield and stronger anti-interference for Hg²⁺. The detection limit was 6.35×10^-8 mol/L, the response time was 25 s. The research also found that MNT could determine Hg²⁺ in the range of pH 4-13. The fluorescence detection mechanism was speculated through nuclear magnetic titration experiments and the coordination ratio 2:1 was determined by Job's curve. The results of the application in practical water samples indicated that MNT could be used as a fluorescent probe for Hg²⁺.