一种裸眼识别的反应型荧光增强铜离子探针

High Sensitivity of Cu2 and Naked Eye Recognition of Flavonoids Fluorescent Probe

摘要:

基于2-吡啶甲酸酯的水解机制，设计合成了一种反应型荧光探针2-（4-（二甲氨基）苯基）4-氧-4H-色酮-7-基-吡啶甲酸酯（IV），并用1H NMR、13C NMR、MS和元素分析进行了结构表征。该探针在Tris-HCl缓冲溶液/乙腈（3/2，V/V）溶液中，室温下能够快速（5 min）的与Cu2+离子发生特异性反应，引起荧光增强（565 nm），同时裸眼可见颜色由红变为淡黄。Cu2+浓度在0 ~ 2.0×10-5 mol·L-1内呈良好的线性关系，检出限为1.67×10-8 mol/L，可用于水质检测。机制研究表明，Cu2+可催化IV的酯键断裂，生成具有强荧光的N,N-二甲胺基黄酮（Ⅲ）。

Abstract:

A novel reaction-based probe (IV), 2-(4-(dimethylamino)phenyl)-4-oxo-4H-chromen-7-yl picolinate was designed and synthesized by utilizing 2-picolinate as the recognition unit. The probe was identified by 1H NMR, 13C NMR, MS and elemental analysis, and it exhibited excellent selectivity for Cu2+ among many common metal ions in HCl-Tris buffer/CH3CN (3:2, V/V) solution, its fluorescence was considerably enhanced by the addition of Cu2+ at room temperature in 5 min, and the color of the solution was changed from red to yellow which can be identified by naked eyes. A linear relationship was observed between the fluorescence intensity and the concentration of Cu2+ in the range of 0 ~ 2.0×10-5 mol·L-1. The detection limit of IV for Cu2+ is 1.67×10-8 mol/L and it can be applied in water quality detection. Mechanism study suggested that Cu2+ promoted the hydrolysis of IV via the catalytic sensing cycle, generating a highly fluorescent N,N-dimethylamine flavonoid (III).