Department of Biomolecular Sciences, Molecular Pathology Laboratory PaoLa, University of Urbino Carlo Bo, Via Arco d'Augusto 2, I-61032 Fano (PU), Italy.
Chemistry. 2012 Apr 2;18(14):4274-84. doi: 10.1002/chem.201103135. Epub 2012 Feb 23.
Ligand L (4-(7-nitrobenzo[1,2,5]oxadiazole-4-yl)-1,7-dimethyl-1,4,7,10-tetra-azacyclododecane) is a versatile fluorescent sensor useful for Cu(II), Zn(II) and Cd(II) metal detection, as a building block of fluorescent metallo-receptor for halide detection, and as an organelle marker inside live cells. Ligand L undergoes a chelation-enhanced fluorescence (CHEF) effect upon metal coordination in acetonitrile solution. In all three complexes investigated the metal cation is coordinatively unsaturated; thus, it can bind secondary ligands as anionic species. The crystal structure of ZnLCl is discussed. Cu(II) and Zn(II) complexes are quenched upon halide interaction, whereas the CdL species behaves as an OFF-ON sensor for halide anions in acetonitrile solution. The mechanism of the fluorescence response in the presence of the anion depends on the nature of the metal ion employed and has been studied by spectroscopic methods, such as NMR spectroscopy, UV/Vis and fluorescence techniques and by computational methods. Subcellular localization experiments performed on HeLa cells show that L mainly localizes in spot-like structures in a polarized portion of the cytosol that is occupied by the Golgi apparatus to give a green fluorescence signal.
配体 L（4-(7-硝基苯并[1,2,5]恶二唑-4-基)-1,7-二甲基-1,4,7,10-四氮杂环十二烷）是一种多功能荧光传感器，可用于 Cu(II)、Zn(II) 和 Cd(II) 金属检测，可用作用于卤化物检测的荧光金属受体的构建块，也可用作活细胞内细胞器的标记物。配体 L 在乙腈溶液中与金属配位时会发生螯合增强荧光（CHEF）效应。在所研究的所有三种配合物中，金属阳离子都是配位不饱和的；因此，它可以作为阴离子结合次级配体。讨论了ZnLCl的晶体结构。Cu(II)和 Zn(II)配合物在与卤化物相互作用时被猝灭，而CdL物种在乙腈溶液中对卤化物阴离子表现为 OFF-ON 传感器。在阴离子存在下荧光响应的机制取决于所使用的金属离子的性质，并通过光谱方法（如 NMR 光谱、UV/Vis 和荧光技术）和计算方法进行了研究。在 HeLa 细胞上进行的亚细胞定位实验表明，L 主要定位于由高尔基体占据的细胞质极化部分中的点状结构，产生绿色荧光信号。
