Development of Nano-Sized Lanthanide Complexes for Supramolecular Recognition

稀土配合物因其独特的化学性质和物理性质，近年来作为特殊的催化剂、有效的核磁共振试剂和其他功能器件受到了人们的广泛关注。其中，发光稀土配合物在阴离子传感、基因组和蛋白质组筛选、生物成像及相关技术等方面具有广阔的应用前景。除了长寿命、高强度和线状发光外，它们还具有广泛的配位数和多种多样的配位结构，这为进一步研究提供了一种新的、有效的策略。我们证明了几种稀土配合物与共存物种高度配位配位后，改变了它们的结构和化学计量比，并成功地将它们用作纳米级客体物种的选择性和发光受体。设计了一种新型的三脚架配体，用于提供阴离子依赖的稀土络合和发光。进一步开发了它们的树状大分子衍生物，用于阴离子响应型稀土配合物的功能化。它同时结合了几个稀土阳离子以响应共存的阴离子，并表现出与客体相关的近红外发光响应。基于稀土络合物的SPR方法可以高度灵敏His标记的蛋白质，其中稀土络合物受体与目的蛋白的寡组氨酸部分发生了高度配位的络合作用。这些结果清楚地表明，稀土配位化学可以为发展纳米级分子识别系统提供一种有效的策略。

Lanthanide complexes have received recent attention as specific catalysts, effective MRI reagents, and other functional devices based on unique chemical and physical properties. Among them, luminescent lanthanide complexes offered further applications in anion sensing, genomic and proteomic screening, biological imaging and related technologies. In addition to long-lived, highly intense, and line-shaped luminescence, they have a wide variety of coordination numbers and versatile coordination structures, which can provide a new, effective strategy for further sophistications.We demonstrated that several lanthanide complexes altered their structures and stoichiometries upon highly coordinated complexation with co-existing species, and successfully applied them as selective and luminescent receptors for nano-scaled guest species. A novel type of tripode ligands were designed to provide anion-dependent lanthanide complexation and luminescence. Their dendrimer derivative was further developed for functionalization of anion-responsive lanthanide complexes. This simultaneously incorporated several lanthanide cations in response to co-existing anions, and exhibited guest-dependent near-infrared luminescence responses. His-tagged protein was highly sensed by lanthanide complex-based SPR method, in which highly coordinated complexation between lanthanide complex receptor and oligohistidine moiety of the targeted protein significantly occurred. These results clearly indicate that lanthanide coordination chemistry can offer an effective strategy for development of nano-size molecular recognition systems.