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-CH₃) to give TpPa-CH₃. The carboxylic acid functionalized TpPa-COOH outperformed the methyl-bearing counterpart TpPa-CH₃ 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_m, of 5.69 mg g⁻¹, 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，也是淡水中新出现的令人担忧的蓝藻毒素，食用受污染的贝类会导致人类麻痹性贝类中毒。为了有效监测这种生物毒素，找到高亲和力的吸附材料非常重要。在此，我们报告了一种用于有效吸附 STX 的共价有机聚合物的设计和合成。通过 2,4,6-三甲酰基间苯三酚 (Tp) 与 2,5-二氨基苯甲酸 (Pa-COOH) 自组装得到 TpPa-COOH 和 2,5-二氨基甲苯，制备了两种基于 β-酮烯胺的材料(Pa-CH ₃ ) 得到 TpPa-CH ₃。羧酸功能化的 TpPa-COOH 优于含甲基的对应物 TpPa-CH ₃尽管后者的长程有序度和表面积更高，但仍提高了一个数量级。TpPa-COOH 对 STX 的吸附速度很快，在 1 小时内达到平衡，Langmuir 吸附模型计算得出的最大吸附容量Q _m为 5.69 mg g ^-1，使该材料成为该毒素的最佳吸附剂。更重要的是，制备的 TpPa-COOH 还显示出天然淡水中 STX 的良好可重用性和高回收率，从而突出表明该材料是从水生环境中提取和预浓缩 STX 的良好候选材料。