Designed porous materials, such as covalent organic frameworks (COFs), are promising materials for the removal of toxic metals from wastewater. To assess the contamination and removal of toxic metal ions, their ultrasensitive detection is extremely important. However, to date, there have been very few reports on the ultrasensitive (picomolar) detection of toxic metal ions using highly porous COFs. Therefore, in this study, we synthesized a highly porous and durable COF containing amine and sulfonyl groups using the hydrothermal method. We demonstrated the impressive performance of obtained COF for the selective and ultrasensitive detection of Hg²⁺. Owing to its excellent luminescence properties and highly p-conjugated system, this metal-free COF can be used as a signal transducer for the selective and sensitive detection of Hg²⁺ at the picomolar level (640 pM). We studied the influence of various factors (e.g., pH, concentration, and temperature) on the sensitive detection of Hg²⁺. Owing to excellent luminescence properties and ultrasensitive detection of Hg²⁺, COF works as highly adsorbent materials for Hg²⁺ with the effective removal capacity of 99.8% at neutral pH. The obtained COF was also applied as a probe for the simultaneous detection and removal of Hg²⁺ in a natural river water sample. The results indicate a new path toward metal-free chemical sensors for toxic pollutants.

设计的多孔材料，例如共价有机骨架（COF），是从废水中去除有毒金属的有前途的材料。为了评估有毒金属离子的污染和清除，其超灵敏检测非常重要。但是，迄今为止，关于使用高度多孔的COF进行有毒金属离子的超灵敏（皮摩尔）检测的报道很少。因此，在这项研究中，我们使用水热法合成了含有胺和磺酰基的高度多孔且耐用的COF。我们证明了获得的COF在Hg ²⁺的选择性和超灵敏检测中的出色表现。由于其出色的发光性能和高度p共轭体系，这种不含金属的COF可用作信号传感器，用于以皮摩尔级（640 pM）选择性和灵敏地检测Hg ²⁺。我们研究了各种因素（例如pH值，浓度和温度）对Hg ²⁺灵敏检测的影响。由于出色的发光特性和对Hg ^2+的超灵敏检测，COF可以作为Hg ^2+的高吸附材料，在中性pH下的有效去除率为99.8％。所获得的COF还用作探针，用于同时检测和去除Hg ²⁺在天然河水样品中。结果表明，有毒污染物的无金属化学传感器的新途径。