Institute for Organic Chemistry, Julius-Maximilians University Würzburg, Am Hubland, 97074, Würzburg, Germany.
Institute for Inorganic Chemistry, Julius-Maximilians University Würzburg, Würzburg, Am Hubland, 97074, Würzburg, Germany.
Chemistry. 2021 Jun 1;27(31):8118-8126. doi: 10.1002/chem.202100594. Epub 2021 May 10.
Detection of metals in different environments with high selectivity and specificity is one of the prerequisites of the fight against environmental pollution with these elements. Pyrenes are well suited for the fluorescence sensing in different media. The applied sensing principle typically relies on the formation of intra- and intermolecular excimers, which is however limiting the sensitivity range due to masking of e. g. quenching effects by the excimer emission. Herein we report a highly selective, structurally rigid chemical sensor based on the monomer fluorescence of pyrene moieties bearing triazole groups. This sensor can quantitatively detect Cu , Pb and Hg in organic solvents over a broad concentrations range, even in the presence of ubiquitous ions such as Na , K , Ca and Mg . The strongly emissive sensor's fluorescence with a long lifetime of 165 ns is quenched by a 1 : 1 complex formation upon addition of metal ions in acetonitrile. Upon addition of a tenfold excess of the metal ion to the sensor, agglomerates with a diameter of about 3 nm are formed. Due to complex interactions in the system, conventional linear correlations are not observed for all concentrations. Therefore, a critical comparison between the conventional Job plot interpretation, the method of Benesi-Hildebrand, and a non-linear fit is presented. The reported system enables the specific and robust sensing of medically and environmentally relevant ions in the health-relevant nM range and could be used e. g. for the monitoring of the respective ions in waste streams.
在不同环境中具有高选择性和特异性地检测金属是对抗这些元素环境污染的前提条件之一。吡喃适合于在不同介质中进行荧光传感。所应用的传感原理通常依赖于形成分子内和分子间的激基缔合物，然而，由于激基缔合物发射的掩蔽效应，例如猝灭效应，这限制了灵敏度范围。在此，我们报告了一种基于带有三唑基团的吡喃部分的单体荧光的高选择性、结构刚性化学传感器。该传感器可以在有机溶剂中定量检测 Cu 、Pb 和 Hg ，浓度范围很宽，即使存在普遍存在的离子，如 Na 、K 、Ca 和 Mg 也是如此。强发光传感器的荧光具有 165 ns 的长寿命，在乙腈中加入金属离子时，通过 1:1 络合物形成而被猝灭。当向传感器中加入金属离子的十倍过量时，会形成直径约为 3 nm 的聚集体。由于系统中的复杂相互作用，对于所有浓度都没有观察到常规线性相关性。因此，对传统的 Job 图解释、Benesi-Hildebrand 方法和非线性拟合进行了批判性比较。所报道的系统能够在与健康相关的 nM 范围内特异性和稳健地检测医学和环境相关的离子，并且可用于例如监测废水中的相应离子。
