基于氨基苯甲酰肼衍生物的铬离子荧光探针的合成及性能研究

Derivatives of Aminobenzoic Acid Hydrazide-Based Fluorescence Probe for Selective Recognition of Cr^(3+)

以对氨基苯甲酸为母体通过系列化学衍生引入丹磺酰胺荧光基团及2-羟基-1-萘醛配位基团构筑了新型、简单的铬离子荧光探针L(1-(二甲基氨基)-5-(4-((2-羟基-1-萘亚甲基)甲酰肼基)苯基)萘磺酰胺)。运用核磁、质谱、元素分析和红外等手段表征了其结构,并通过荧光光谱法研究了探针分子L对Cr^(3+)的识别作用。结果表明,当激发波长为350nm时,单纯的探针分子L在473nm(2-羟基-1-萘醛)和514nm(丹磺酰胺)处显示连体双峰;当向探针分子L中加入Cr^(3+)后,2-羟基-1-萘醛作为受体与Cr^(3+)结合,丹磺酰胺发射峰红移至540nm,并且强度增强5倍,量子产率Φ=0.28。探针分子L的背景荧光对Cr^(3+)的识别无任何影响,识别过程推测是由CHEF效应和PET(光诱导电子转移)共同引起的。当加入其他金属离子(Na^+,K^+,Li^+,Ca^(2+),Zn^(2+),Mn^(2+),Co^(2+),Cu^(2+),Cd^(2+),Hg^(2+),Pb^(2+),Ag^+)时,在540nm处荧光强度未增强,表明L对Cr^(3+)具有高度专一的选择性。通过电喷雾质谱和Job's plot曲线确定L和Cr^(3+)为1∶1的配位模式,探针L对Cr^(3+)的最低检测限可达到4.0×10^(-6 )mol·L^(-1)。

A novel and simple fluorescence probe L((E)-4-(1-(dimethylamino)naphthalene-5-sulfonamido)-N′-((2-hydroxynaphthalen-1-yl)methylene)benzohydrazide)for detection of Cr 3+was prepared by the introduction of dansyl sulfonamide fluorescent group and 2-hydroxy-1-naphthalaldehyde coordination group to p-aminobenzoic acid with chemical derivatization method.The structure of the probe L was investigated by 1H NMR,ESI-MS and FT-IR.The effect of probe L for recognition of Cr 3+was studied by fluorescence spectroscopy.The results show that the probe L shows a double peak at 473 nm(2-hydroxy-1-naphthaldehyde)and 514 nm(dansyl sulfonamide)when the excitation wavelength is350 nm.After the addition of Cr 3+to the probe L,2-hydroxy-1-naphthaldehyde was bonded to Cr 3+,and the emission peak of dansylamine was red shifted to 540 nm(dansylamine characteristic peak).The intensity of fluorescencewas increased by five times and the fluorescence quantum yieldΦwas up to0.28.The background fluorescence of the probe L has no effect on the recognition of Cr 3+.The recognition process is presumed to be caused by the CHEF effect combined with PET(photoinduced electron transfer)mechanism.When theother metal ions were added,such as Na+,K+,Li+,Ca 2+,Zn2+,Mn 2+,Co 2+,Cu 2+,Cd 2+,Hg 2+,Pb2+,Ag+,the fluorescence intensity was not enhanced at 540 nm,indicating that the probe L had a high specific selectivity for Cr 3+.A 1∶1 complexation stoichiometry for the binding mode of Cr 3+with L was confirmed bythe model of the Job’s plot and ESI-MS result.The detection limit of L forCr 3+was up to 4.0×10-6 mol·L-1.