Carbon-Decorated Fe3O4 Nanocomposites as Enhanced Enzyme Mimics for Colorimetric Determination of H2O2 and Glucose

The development of sensitive and accurate glucose biosensors is significant in diabetic patient monitoring. Here, we synthesize carbon-decorated Fe3O4 nanotubes (Fe3O4@C NTs) using a rational designed template method. Through catalytic oxidation of a typical colorimetric reaction, the prepared Fe3O4@C NTs showed significantly better peroxidase-like and oxidase-like performances than other similar Fe3O4-based nanomaterials. Moreover, the optimal pH, temperature, and concentration for Fe3O4@C NTs were 4.0, 60 °C, and 40 μg/mL, respectively. We additionally investigated the steady-state kinetics of Fe3O4@C NTs, and their catalyzed reactions were found to follow the typical Michaelis–Menten model. Based on the peroxidase-like activity of Fe3O4@C NTs, they were employed for label-free, rapid, selective, and highly sensitive colorimetric detection of H2O2 and glucose, demonstrating a potential application for glucose determination.