Oxygen-functionalized Fe3O4@o-polypyrrole acting as high-efficiency oxidase mimics and their application in glutathione colorimetric sensing

The enzyme-like properties of nanozymes may be considerably affected by the structure and surface groups, which thus need to be optimized. Here, through a simple NaOH chemical corrosion method, the chemical structure similar to N-Methylpyrrolidone (NMP), which possessed intrinsic oxidase-like activity, was introduced into polypyrrole (PPy), and then this nanomaterial became oxygen-functionalized PPy ( o -PPy) with excellent oxidase-like activity from PPy without this property. Furthermore, after compounding magnetic Fe 3 O 4 , the obtained nanocomposites Fe 3 O 4 @o-PPy nanoparticles (Fe 3 O 4 @o-PPy NPs) showed superiorities in separation during synthesis and real-time control of enzyme catalysis . Studies have found that the enzymatic activity of Fe 3 O 4 @o-PPy NPs depended on the amount of functionalized oxygen and the conjugation extent of o -PPy. Fe 3 O 4 @o-PPy NPs had efficient oxidase-like activity under a wide range of pH and temperature. Based on the oxidase-like activity of Fe 3 O 4 @o-PPy NPs, a colorimetric sensor for glutathione (GSH), which presented rich color changes and satisfactory colorimetric resolution by adding the amaranth , was realized. We believe that the functional modification and structural regulation of PPy can not only realize its wider application but also promote the discovery of novel and efficient nanozymes .