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

Abstract

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.