Sensitive and convenient determination of gallic acid (GA) is vital for food safety. Here, a novel porphyrin (Cu)-based covalent organic framework named as COF(Cu) was successfully synthesized by condensing pre-metalated 5,10,15,20-tetrakis (para-aminophenyl) porphyrin copper (II) and 2,3,6,7-tetra (4-formylphenyl) tetrathiafulvalene ligands. By combining the advantages of porphyrin with tetrathiafulvalene, it may be possible to create a COF with an intrinsically effective charge-transfer channel. In addition, the Cu-N₄ type in the COF(Cu) can be regarded as the single-site electrocatalyst. Benefiting from these advantages, the COF(Cu) based electrochemical sensor demonstrated outstanding response to gallic acid (GA). Under the optimal conditions by square wave voltammetry technique, the COF(Cu) modified electrode showed a wide linear range (0.01–1000 μM), a low detection limit (2.81 nM), good reproducibility, acceptable selectivity as well as high stability. Moreover, the established approach was adopted to detect GA in real tea samples with good recoveries, indicating that the COF(Cu) based electrochemical sensor may pave the way for the application in food analysis.

灵敏、便捷地测定没食子酸 (GA) 对于食品安全至关重要。在这里，通过缩合预金属化的5,10,15,20-四（对氨基苯基）卟啉铜（II）和2,3成功合成了一种新型的卟啉（Cu）基共价有机骨架，命名为COF（Cu） ,6,7-四(4-甲酰基苯基)四硫富瓦烯配体。通过将卟啉与四硫富瓦烯的优点相结合，有可能创建具有本质上有效的电荷转移通道的COF。此外，COF(Cu)中的Cu-N ₄型可以被视为单中心电催化剂。受益于这些优点，基于 COF(Cu) 的电化学传感器对没食子酸 (GA) 表现出出色的响应。在方波伏安技术的最佳条件下，COF(Cu)修饰电极表现出较宽的线性范围（0.01~1000 μM）、较低的检测限（2.81 nM）、良好的重现性、可接受的选择性以及较高的稳定性。此外，采用所建立的方法检测真实茶叶样品中的GA，回收率良好，表明基于COF(Cu)的电化学传感器可以为食品分析中的应用铺平道路。