Study of chiral imaging sensors using induced circularly polarized luminescence from rare earth complexe

由于探针的结构和配合物周围的环境，研究了发射探针分子的诱导圆偏振发光（iCPL）。稀土配合物如[Eu(pda)2]-（pda = 1,10菲罗啉2,9二羧酸）由于其高发射特性和相对较大的g值以及其非手性结构而被选择作为探针。当稀土配合物虽然具有非手性结构，但仍表现出CPL时，这一观察结果意味着配合物的结构被其他手性分子或环境扭曲成手性结构。这种类型的iCPL可用于手性传感系统。CPL传感系统具有应用于高灵敏度显微传感系统和单分子CPL光谱的潜力。在这一观点下，我们寻找了可能扭曲成手性结构的非手性发光稀土配合物，它们在感知手性分子或环境时表现出强烈的CPL信号。我们发现[Eu(pda)2]和[Eu(bda)2]-（bda = 2,2 ' -联吡啶-6,6 ' -二羧酸）在水溶液中对S(R)-2-吡咯烷酮-5-羧酸等氨基酸表现出强烈的iCPL。此外，我们通过显微系统检测了iCPL，并使用[Eu(pda)2]-作为iCPL探针分子对共轭体系进行了iCPL映射。

Induced circularly polarized luminescence （iCPL) from emitting probe molecules has been studied for the structure of the probes and environment around the complex. Rare-earth complexes such as [Eu（pda)2]-（pda = 1,10 phenanthroline 2,9 dicarboxylic acid) have been selected as the probes due to their high emissive properties and relatively large g values, and its achiral structures. When the rare-earth complexes exhibit CPL in spite of their achiral structures, the observation will mean that the structure of the complex is distorted to chiral by other chiral molecules or environments. This type of iCPL is available for chiral sensing system. The CPL sensing system has a potential to be employed in a microscopic sensing system with high sensitivity, and a single molecule CPL spectroscopy. In this view point, we have searched achiral emissive rare earth complexes which are likely distorted to chiral structure and show strong CPL signal when they sense chiral molecules or environments. We found [Eu（pda)2]-and [Eu（bda)2]-（bda = 2,2’-bipyridine-6,6’-dicarboxic acid) exhibits intense iCPL by some amino acids such as S（R)-2-Pyrrolidone-5-Carboxylic acid in aqueous solution. Furthermore, we have examined iCPL detection via microscopic system and made iCPL mapping for a conjugatedsystem using [Eu（pda)2]-as a iCPL probe molecule.