一种基于喹啉酰腙的接力识别Cu^(2+)和草甘膦的荧光探针及其应用

A Novle Quinoline Hydrazone-Based Fluorescent Probe for Sequential Determination of Cu^(2+)/Glyphosate and Its Applications

以喹啉-2-甲酸和7-(二乙氨基)香豆素-3-甲醛为原料,设计合成了一种喹啉酰腙类荧光探针L,并利用紫外/荧光分光光度法考察其光谱性能.研究结果表明,在四氢呋喃(THF)/H_(2)O[V:V=3:7,4-羟乙基哌嗪乙磺酸(HEPES)10 mmol/L,pH=7.4]溶液中,探针L对Cu^(2+)表现出显著的荧光猝灭效应,响应速度快,特异性强,灵敏度高,并且它们之间的结合比为1:1.同时,配合物L-Cu^(2+)对草甘膦表现出显著的荧光增强效应,且不受其它有机磷农药、金属离子和阴离子的干扰,其检测限可达5.6×10^(-8)mol/L(即9.5×10^(-3)mg/L).此外,配合物L-Cu^(2+)能够“裸眼”检测草甘膦,并在实际水样中实现了草甘膦的定量检测.

A novel quinoline hydrazone-based fluorescent probe L was designed and synthesized using quinoline-2-carboxylic acid and 7-(diethylamino)coumarin-3-carbaldehyde as raw materials.The spectral properties of probe L were studied by UV-Vis/fluorescence spectrophotometry.The results showed that probe L had obvious ON-OFF fluorescence response to Cu^(2+)in the tetrahydrofuran(THF)/H_(2)O[V:V=3:7,2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid(HEPES)10 mmol/L,pH=7.4]solution,and it displayed efficiency,high specificity and sensitivity.Job’s plot and high resolution mass spectrometry showed that the stoichiometry of L-Cu^(2+)complex was estimated to be 1:1.Meanwhile,complex L-Cu^(2+)showed high selectivity and good anti-interference ability towards glyphosate through the significant fluorescence enhancement,and the detection limit of complex L-Cu^(2+)to glyphosate could reach 5.6×10^(-8)mol/L(9.5×10^(-3)mg/L).In addition,complex L-Cu^(2+)was able to sense glyphosate by“naked-eye”according to the color change,and applied to glyphosate detection in the actual water samples.