Remarkable tuning of the photophysical properties of bifunctional lanthanide tris(dipicolinates) and its consequence on the design of bioprobes
Remarkable tuning of the photophysical properties of bifunctional lanthanide tris(dipicolinates) and its consequence on the design of bioprobes
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DOI：
10.1021/ic800842f
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发表时间：
2008-09-01
影响因子：
4.6
通讯作者：
Chauvin, Anne-Sophie
中科院分区：
文献类型：
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作者：
Gassner, Anne-Laure;Duhot, Celine;Chauvin, Anne-Sophie
在吡啶4位上带有聚氧乙烯悬挂臂的二吡啶甲酸的衍生物已经被功能化，以用于与生物材料的潜在接枝。合成了四种具有不同末端功能的配体(醇、甲氧基、邻苯二甲酰亚胺和胺)，并与三价稀土离子Ln(III)反应生成了三螺旋的[Ln(L)(3)](3-)配合物。三元络合物表现出很大的热力学稳定性，例如，所有Eu-III络合物的109β13约为19-20。光物理测量表明，Eu(ETA(SENS)=33-72%)和Tb配合物中的金属中心发光具有足够的敏化作用，这受末端功能的性质调制。[Eu(L)(3)](3-)和[Tb(L)(3)](3-)的金属中心激发态的寿命都很长，室温下可达1.4ms和1.6ms，与水化数基本等于零相一致。在生理pH条件下，(Eu(L-NH_2)(3))(3-)和[Tb(L-OH)(3)](3-)的量子产率分别高达29%和18%。这些系列的配合物展示了稀土发光探针可实现微调的程度，是研究与生物分子结合对金属中心发光性质影响的简单模型。
Derivatives of dipicolinic acid with a polyoxyethylene pendant arm at the pyridine 4-position have been functionalized for potential grafting with biological material. Four ligands with different terminal functions (alcohol, methoxy, phtalimide and amine) have been synthesized, which react with trivalent lanthanide ions Ln(III) to yield triple helical [Ln(L)(3)](3-) complexes, as shown by NMR and UV-vis titrations. The tris chelates display large thermodynamic stability with 109 beta 13 approximate to 19-20 for all Eu-III complexes for instance. Photophysical measurements reveal adequate sensitization of the metal-centered luminescence in the europium (eta(sens) = 33-72%) and terbium complexes, which is modulated by the nature of the terminal function. The lifetimes of the metal-centered excited states are long, up to 1.4 ms for [Eu(L)(3)](3-) and 1.6 ms for [Tb(L)(3)](3-) at room temperature, in line with hydration numbers essentially equal to zero. Quantum yields are as high as 29% for the (Eu(L-NH2)(3)](3-) and 18% for the [Tb(L-OH)(3)](3-) tris chelates in water at physiological pH. These series of complexes demonstrate the extent of fine-tuning achievable for lanthanide luminescent probes and are simple models for investigating the effect of binding to biological molecules on the metal-centered luminescent properties.