Abstract：
In this study, a bis-indole compound was synthesized, characterized by 1H NMR, Fourier transform infrared, and mass spectroscopic measurements and used as a selective and efficient probe for the spectrofluorimetric analysis of Co (II). The cobalt-induced quenching in the emission maximum at 567 nm was considered as the analytical signal in calibration studies. When encapsulated in a polymethyl methacrylate (PMMA) matrix, the bis-indole compound exhibited a limit of detection (LOD) of 3.60 × 10-11 M for Co (II). Vitamin B12, which contains a cobalt ion in the center of a corrin ring in its structure, was also successfully quantified using the same probe. The bis-indole compound showed a linear response based on quenching for increasing concentrations of vitamin B12, partially mimicking the contracted tetrapyrrole ring found naturally in the center of vitamin B12. The LOD for vitamin B12 was found to be 76 nm. Promising photophysical properties of the proposed probe, including high molar extinction coefficient, considerable quantum yield (0.46 and 0.64 in tetrahydrofuran and PMMA, respectively), high Stoke\'s shift and satisfactory photostability, make it a good choice for fluorescence-based Co (II) determination. The ML3-type stoichiometry of the complex between the dye and cobalt was elucidated both by Job\'s method and by high-resolution mass spectrometry (HR-MS).
摘要：
在这项研究中,合成了一种双吲哚化合物，通过1HNMR表征，傅里叶变换红外,和质谱测量，并用作选择性和有效的探针，用于Co（II）的荧光光谱分析。在567nm处的发射最大值中的钴诱导猝灭被认为是校准研究中的分析信号。当封装在聚甲基丙烯酸甲酯（PMMA）基质中时，双吲哚化合物对Co（II）的检测限（LOD）为3.60×10-11M。维生素B12在其结构中的corrin环中心含有钴离子，也使用相同的探针成功定量。双吲哚化合物显示出基于对增加的维生素B12浓度的猝灭的线性响应，部分模拟了在维生素B12中心天然存在的收缩的四吡咯环。发现维生素B12的LOD为76nm。所提出的探针具有良好的光物理性质，包括高摩尔消光系数，相当高的量子产率(0.46和0.64在四氢呋喃和PMMA中，分别)，高斯托克的位移和令人满意的光稳定性，使其成为荧光基Co(II)测定的良好选择。通过Job方法和高分辨率质谱（HR-MS）阐明了染料和钴之间络合物的ML3型化学计量。
