The bioaccumulation of heavy metal ions (HMIs), even at low concentrations, will lead to high toxicity. So, in this work, a hydrazone-linked covalent organic framework (COF) with abundant N and O atoms was prepared for sensitive HMIs detection. Under the room temperature, terephthaloyl dihydrazide (TD) and triformylphloroglucinol (TP) reacted to form the hydrazone bond, and a new hydrazone-linked TP-TD COF was prepared. During the reaction, enole-keto tautomerism occurred, and NH···OC hydrogen bond was formed, which improved the crystallinity and chemical stability of COF. Accordingly, the hydrazone-linked TP-TD COF presented three-dimensional network morphology. The porous channels could promote the migration of HMIs, and the affinity of N and O atoms to HMI was utilized. There were abundant O·N·O sites in each unit, so the hydrazone-linked TP-TD COF was applied to the sensing of HMIs. The electrochemical sensor constructed by TP-TD COF was used to detect Cd²⁺, Pb²⁺, Cu²⁺ and Hg²⁺ simultaneously. Under optimized conditions, the electrochemical sensor based on TP-TD COF showed fast response speed, sensitive detection ability and the potential for practical sample detection.

重金属离子 (HMI) 的生物蓄积性，即使在低浓度下，也会导致高毒性。因此，在这项工作中，制备了具有丰富 N 和 O 原子的腙连接的共价有机骨架 (COF)，用于灵敏的 HMI 检测。在室温下，对苯二甲酰二酰肼（TD）与三甲酰间苯三酚（TP）反应形成腙键，制备出一种新的腙连接的TP-TD COF。反应过程中发生烯醇-酮互变异构，N H···O形成C氢键，提高了COF的结晶度和化学稳定性。因此，腙连接的 TP-TD COF 呈现三维网络形态。多孔通道可以促进 HMI 的迁移，并利用 N 和 O 原子对 HMI 的亲和力。每个单元中都有丰富的O·N·O位点，因此将腙连接的TP-TD COF应用于HMIs的传感。采用TP-TD COF构建的电化学传感器同时检测Cd ²⁺、Pb ²⁺、Cu ²⁺和Hg ²⁺。在优化条件下，基于TP-TD COF的电化学传感器表现出快速的响应速度、灵敏的检测能力和实际样品检测的潜力。