Singer Helena, Drobot Björn, Zeymer Cathleen, Steudtner Robin, Daumann Lena J
Department of Chemistry, Ludwig-Maximilians-University Munich Butenandtstraße 5 - 13 81377 München Germany
Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf e.V. Bautzner Landstraße 400 01328 Dresden Germany
Chem Sci. 2021 Oct 26;12(47):15581-15587. doi: 10.1039/d1sc04827a. eCollection 2021 Dec 8.
The separation and recycling of lanthanides is an active area of research with a growing demand that calls for more environmentally friendly lanthanide sources. Likewise, the efficient and industrial separation of lanthanides from the minor actinides (Np, Am-Fm) is one of the key questions for closing the nuclear fuel cycle; reducing costs and increasing safety. With the advent of the field of lanthanide-dependent bacterial metabolism, bio-inspired applications are in reach. Here, we utilize the natural lanthanide chelator lanmodulin and the luminescent probes Eu and Cm to investigate the inter-metal competition behavior of all lanthanides (except Pm) and the major actinide plutonium as well as three minor actinides neptunium, americium and curium to lanmodulin. Using time-resolved laser-induced fluorescence spectroscopy we show that lanmodulin has the highest relative binding affinity to Nd and Eu among the lanthanide series. When equimolar mixtures of Cm and Am are added to lanmodulin, lanmodulin preferentially binds to Am over Cm whilst Nd and Cm bind with similar relative affinity. The results presented show that a natural lanthanide-binding protein can bind a major and various minor actinides with high relative affinity, paving the way to bio-inspired separation applications. In addition, an easy and versatile method was developed, using the fluorescence properties of only two elements, Eu and Cm, for inter-metal competition studies regarding lanthanides and selected actinides and their binding to biological molecules.
镧系元素的分离和回收是一个活跃的研究领域，需求不断增长，这就需要更环保的镧系元素来源。同样，从次要锕系元素（Np、Am - Fm）中高效且工业化地分离镧系元素是关闭核燃料循环的关键问题之一；即降低成本并提高安全性。随着镧系元素依赖性细菌代谢领域的出现，受生物启发的应用已触手可及。在此，我们利用天然镧系元素螯合剂镧调蛋白以及发光探针铕（Eu）和锔（Cm）来研究所有镧系元素（钷（Pm）除外）、主要锕系元素钚以及三种次要锕系元素镎、镅和锔与镧调蛋白的金属间竞争行为。使用时间分辨激光诱导荧光光谱法，我们表明在镧系元素系列中，镧调蛋白对钕（Nd）和铕具有最高的相对结合亲和力。当将等摩尔的锔和镅混合物添加到镧调蛋白中时，镧调蛋白优先结合镅而非锔，而钕和锔以相似的相对亲和力结合。所呈现的结果表明，一种天然的镧系元素结合蛋白可以以高相对亲和力结合主要和各种次要锕系元素，为受生物启发的分离应用铺平了道路。此外，还开发了一种简单且通用的方法，利用仅铕和锔这两种元素的荧光特性，用于研究镧系元素和选定锕系元素的金属间竞争及其与生物分子的结合。
