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

Abstract

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 nm.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.