Wang Tianxing, Fernandes Soraia P S, Araújo Joana, Li Xiaoxi, Salonen Laura M, Espiña Begoña
International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, 4715-330 Braga, Portugal; Ministry of Education Engineering Research Center of Starch and Protein Processing, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China.
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.
J Hazard Mater. 2023 Jun 15;452:131247. doi: 10.1016/j.jhazmat.2023.131247. Epub 2023 Mar 22.
Saxitoxin (STX), the most widely distributed neurotoxin in marine waters and emerging cyanotoxin of concern in freshwaters, causes paralytic shellfish poisoning in humans upon consumption of contaminated shellfish. To allow for the efficient monitoring of this biotoxin, it is of high importance to find high-affinity materials for its adsorption. Herein, we report the design and synthesis of a covalent organic polymer for the efficient adsorption of STX. Two β-keto-enamine-based materials were prepared by self-assembly of 2,4,6-triformylphloroglucinol (Tp) with 2,5-diaminobenzoic acid (Pa-COOH) to give TpPa-COOH and with 2,5-diaminotoluene (Pa-CH) to give TpPa-CH. The carboxylic acid functionalized TpPa-COOH outperformed the methyl-bearing counterpart TpPa-CH by an order of magnitude despite the higher long-range order and surface area of the latter. The adsorption of STX by TpPa-COOH was fast with equilibrium reached within 1 h, and the Langmuir adsorption model gave a calculated maximum adsorption capacity, Q, of 5.69 mg g, making this material the best reported adsorbent for this toxin. More importantly, the prepared TpPa-COOH also showed good reusability and high recovery rates for STX in natural freshwater, thereby highlighting the material as a good candidate for the extraction and pre-concentration of STX from aquatic environments.
石房蛤毒素（STX）是海水中分布最广的神经毒素，也是淡水中备受关注的新出现的蓝藻毒素，人类食用受污染的贝类后会引发麻痹性贝类中毒。为了能够高效监测这种生物毒素，找到对其具有高亲和力的吸附材料至关重要。在此，我们报告了一种用于高效吸附STX的共价有机聚合物的设计与合成。通过2,4,6-三甲基间苯三酚（Tp）与2,5-二氨基苯甲酸（Pa-COOH）自组装制备了两种基于β-酮烯胺的材料，得到TpPa-COOH，以及与2,5-二氨基甲苯（Pa-CH）自组装得到TpPa-CH。尽管TpPa-CH具有更高的长程有序性和表面积，但羧酸官能化的TpPa-COOH在吸附性能上比含甲基的对应物TpPa-CH高出一个数量级。TpPa-COOH对STX的吸附速度很快，1小时内即可达到平衡，朗缪尔吸附模型计算得出的最大吸附容量Q为5.69 mg/g，使该材料成为报道的对这种毒素吸附性能最佳的吸附剂。更重要的是，制备的TpPa-COOH在天然淡水中对STX还表现出良好的可重复使用性和高回收率，从而突出了该材料作为从水生环境中提取和预浓缩STX的良好候选材料的特性。
