International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, 4715-330 Braga, Portugal.
Associate Laboratory for Green Chemistry-Network of Chemistry and Technology (LAQV-REQUIMTE), Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
ACS Appl Mater Interfaces. 2021 Apr 7;13(13):15053-15063. doi: 10.1021/acsami.0c18808. Epub 2021 Mar 24.
Microcystins (MCs), produced by sp, are the most commonly detected cyanotoxins in freshwater, and due to their toxicity, worldwide distribution, and persistence in water, an improvement in the monitoring programs for their early detection and removal from water is necessary. To this end, we investigate the performance of three covalent organic frameworks (COFs), TpBD-(CF), TpBD-(NO), and TpBD-(NH), for the adsorption of the most common and/or toxic MC derivatives, MC-LR, MC-RR, MC-LA, and MC-YR, from water. While MC-LR and MC-YR can be efficiently adsorbed using all three COF derivatives, high adsorption efficiencies were found for the most lipophilic toxin, MC-LA, with TpBD-(NH), and the most hydrophilic one, MC-RR, with TpBD-(NO). Theoretical calculations revealed that MC-LA and MC-RR have a tendency to be located mainly on the COF surface, interacting through hydrogen bonds with the amino and nitro functional groups of TpBD-(NH) and TpBD-(NO), respectively. TpBD-(NO) outperforms the adsorbent materials reported for the capture of MC-RR, resulting in an increase in the maximum adsorption capacity by one order of magnitude. TpBD-(NH) is reported as the first efficient adsorbent material for the capture of MC-LA. Large differences in desorption efficiencies were observed for the MCs with different COFs, highlighting the importance of COF-adsorbate interactions in the material recovery. Herein we show that efficient capture of these toxins from water can be achieved through the proper selection of the COF material. More importantly, this study demonstrates that by careful choice of COF functionalities, specific compounds can be targeted or excluded from a group of analogues, providing insight into the design of more efficient and selective adsorbent materials.
微囊藻毒素（MCs）是由 sp 产生的，是淡水中最常见的氰类毒素，由于其毒性、全球分布和在水中的持久性，需要改进监测计划以早期检测和从水中去除它们。为此，我们研究了三种共价有机框架（COFs），TpBD-（CF）、TpBD-（NO）和 TpBD-（NH），用于从水中吸附最常见和/或毒性最大的 MC 衍生物，如 MC-LR、MC-RR、MC-LA 和 MC-YR。虽然所有三种 COF 衍生物都可以有效地吸附 MC-LR 和 MC-YR，但发现疏水性最强的毒素 MC-LA 在 TpBD-（NH）上的吸附效率最高，亲水性最强的毒素 MC-RR 在 TpBD-（NO）上的吸附效率最高。理论计算表明，MC-LA 和 MC-RR 倾向于主要位于 COF 表面，通过氢键与 TpBD-（NH）和 TpBD-（NO）的氨基和硝基官能团相互作用。TpBD-（NO）在捕获 MC-RR 方面优于报道的吸附材料，使最大吸附容量增加了一个数量级。TpBD-（NH）被报道为第一个有效捕获 MC-LA 的吸附材料。不同 COF 对 MC 的解吸效率存在较大差异，这突出了 COF-吸附剂相互作用在材料回收中的重要性。本文证明，通过选择合适的 COF 材料，可以从水中有效地捕获这些毒素。更重要的是，这项研究表明，通过仔细选择 COF 的功能，特定的化合物可以被靶向或从一组类似物中排除，为设计更高效和选择性的吸附材料提供了思路。
