Iron‐Porphyrin‐Based Covalent Assembly with Peroxidase‐Like Activity and High Efficiency for Cr(VI) Colorimetric Detection

Efficient synthesis of functional nanomaterials for simple, sensitive, and accurate colorimetric detection of chromate [Cr(VI)] has attracted great interest due to the toxicity of Cr(VI). Here, novel covalently assembled iron porphyrins (CAIPs) are fabricated through covalently cross‐linking reaction between iron‐tetra‐(4‐hydroxy‐phenyl) porphyrin and three different cross‐linkers based on 3,3´‐dithiodipropionic acid. The results show that CAIPs have a spherical vesicle framework with favorable dimensional structure and enzymatic activity. In the presence of H 2 O 2 , CAIPs exhibit high peroxidase‐like activity toward 3,3´,5,5´‐tetramethylbenzidine. Based on these findings, CAIPs are used as an efficient colorimetric catalyst for the sensitive and selective detection of Cr(VI) with a detection limit about 23 n m . The feasibility of this method for real‐water samples is verified by a standard addition experiment. This system further facilitates the developments of nanomaterial, and its application in colorimetric detection fields.