Metalloporphyrin-based Amphiphilic Porous Organic Polymer with Peroxidase-mimetic Activity for Colorimetric Detection of Ascorbic Acid

Porous organic polymers (POPs) are a class of materials that combine the properties of both polymers and porosity. They are characterized by their network structure composed of repeating organic units, which form pores or cavities throughout the material. Owing to their unique features including tunable porosity, abundant accessible active sites and synthetically control ability, POPs have been widely employed in the fields of catalysis, adsorption, and biomedicine. The incorporation of porphyrin building units into POPs endows POPs with unique structural characteristics and excellent optical properties. In this work, the aldehyde porphyrin with polyethylene glycol chain was successfully synthesized with good hydrophilicity, which was then reacted with tetrakis(4-aminophenyl) methane to construct the porphyrin-based porous organic polymers. The porphyrin-based POPs was then metallized to yield iron-containing porous organic polymers (Fe-POPs), which could catalyze the transformation of colorless substrate (3,3′,5,5′-tetramethylbenzidine (TMB)) to a blue product (ox-TMB) in the presence of hydrogen peroxide (H 2 O 2 ). Upon the addition of the ascorbic acid (AA) to the aforementioned system, the blue solution faded gradually to colorless. Based on this phenomenon, a rapid and sensitive colorimetric assay for the measurement of H 2 O 2 and AA was developed using Fe-POPs as mimetic enzyme. Fe-POPs was then successfully applied in real samples to detect AA with high accuracy. As a potential peroxidase mimic, Fe-POPs demonstrated the benefits of excellent stability and catalytic efficiency, which presented the promising application in the area of biocatalysis and biosensing. Graphical