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Cr3+的识别作用。 结果表明， 当激发波长为350 nm时， 单纯的探针分子L在473 nm（2-羟基-1-萘醛）和514 nm（丹磺酰胺）处显示连体双峰； 当向探针分子L中加入Cr3+后， 2-羟基-1-萘醛作为受体与Cr3+结合， 丹磺酰胺发射峰红移至540 nm， 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Cr3+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+， Ca2+， Zn2+， Mn2+， Co2+， Cu2+， Cd2+， Hg2+， Pb2+， Ag+）时， 在540 nm处荧光强度未增强， 表明L对Cr3+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Cr3+为1∶1的配位模式， 探针L对Cr3+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 Cr3+ 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 Cr3+ 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 is 350 nm. After the addition of Cr3+ to the probe L, 2-hydroxy-1-naphthaldehyde was bonded to Cr3+, and the emission peak of dansylamine was red shifted to 540 nm (dansylamine characteristic peak). The intensity of fluorescence was increased by five times and the fluorescence quantum yield Φ was up to 028. The background fluorescence of the probe L has no effect on the recognition of Cr3+. The recognition process is presumed to be caused by the CHEF effect combined with PET (photoinduced electron transfer) mechanism. When the other metal ions were added, such as Na+, K+, Li+, Ca2+, Zn2+, Mn2+, Co2+, Cu2+, Cd2+, Hg2+, Pb2+, Ag+, the fluorescence intensity was not enhanced at 540 nm, indicating that the probe L had a high specific selectivity for Cr3+. A 1∶1 complexation stoichiometry for the binding mode of Cr3+ with L was confirmed by the model of the Job’s plot and ESI-MS result. The detection limit of L for Cr3+ was up to 40×10-6 mol·L-1.