Abstract: Silica-immobilized ionic liquid modified magnetic nanoparticles (Fe3O4@SiO2@IL) were prepared and applied as a peroxidase mimic for the detection of H2O2. The results showed that Fe3O4@SiO2@IL had higher catalytic activity than horseradish peroxidase (HRP), and could catalyze the coupling of H2O2 with the peroxidase substrate 3,3’,5,5’-tetramethyl aniline (TMB) to form a blue product. On the basis of this phenomenon, a colorimetric method for H2O2 detection was developed, with a linear range of 4–100 μmol/L and a detection limit of 0.698 μmol/L. The method was also available to sensitively and selectively detect glucose, with a linear range of 8–200 μmol/L and a detection limit of 2.39 μmol/L. The recoveries for this method when applied to detect H2O2 in milk samples ranged from 94.0% to 107.8%, with relative standard deviation (RSD) values of 2.24%–3.12%, showing high accuracy and precision. Therefore, Fe3O4@SiO2@IL nanomaterials with peroxidase mimic activity can be a promising candidate for application in clinical diagnosis, pharmaceutical, food and other fields.

Key words: colorimetric sensor; ionic liquid; nanoenzyme; hydrogen peroxide; glucose; food detection