Covalent organic framework with extraordinary intrinsic catalytic activity for electrochemical sensing of iodide ions

Abstract

Environmental conservation and food safety have aroused enormous concerns owing to their close relationship with human health. Iodide ion (I−) could result in serious diseases in mankind. Thus, it is challenging and essential to develop an effective approach to capture and detect I−. Herein, the TT-COF(Zn) material prepared using 2,3,6,7-tetra (4-formyl phenyl) tetrathiafulvalene (TTF) and 5,10,15,20-tetrakis(para-aminophenyl) porphyrin Zinc (II) (TPZ) as building blocks were designed directly as electrode modified material for electrochemical sensing of I−. Combining the meritsofTPZ and TTF to construct the intrinsic efficient electron-transfer pathways, as well as the advantages of porous channel and single-site catalysis of COF, TT-COF(Zn) material-modified electrode showed excellent electrocatalytic performance towards the redox reaction of I−, which makes it a sensitive sensing platform for the electrochemical quantification of I−. After a series of optimization experiments, the I− sensor demonstrated a wide linear range (0.02–15 mM), low detection limit (3.15 μM), as well as other good sensing features. The proposed sensor also performed well in the determination of I− in real river samples. This work not only offers a simple method to assay I− effectively but also paves a way for the strategical design and synthesis of COFs for electrochemical sensing applications.