Carbon dots/Fe3O4 hybrid nanofibers as efficient peroxidase mimics for sensitive detection of H2O2 and ascorbic acid

Abstract

In recent years, carbon dots (CDs) based hybrid nanomaterials have received considerable attention due to their outstanding optical and catalytic properties. Herein, CDs/Fe₃O₄ hybrid nanofibers are prepared via a facile electrospinning technique combined with a hydrothermal reaction and a thermochemical reduction process. During the synthetic process, α-Fe₂O₃ nanofibers are synthesized via electrospinning followed by a calcination process first. Then CDs modified α-Fe₂O₃ nanofibers can be obtained under a hydrothermal reaction. Finally, the prepared CDs modified α-Fe₂O₃ nanofibers are converted to CDs/Fe₃O₄ hybrid nanofibers through a thermochemical reduction process. The resulting CDs/Fe₃O₄ hybrid nanofibers show a superior peroxidase catalytic activity to individual CDs, α-Fe₂O₃ nanofibers, CDs/α-Fe₂O₃ hybrid nanofibers and commercial Fe₃O₄ nanoparticles. The steady-state kinetic assay exhibits an excellent affinity for TMB with a low Michaelis–Menten constant (K_m) value. On the basis of the high peroxidase-like activity of CDs/Fe₃O₄ hybrid nanofibers, a simple approach for the colorimetric detection of H₂O₂ and ascorbic acid (AA) with a low detection limit of 0.917 and 0.285 μM, respectively, is developed. This work inspires researchers to develop functional hybrid nanomaterials for fabricating superior biomimetic catalysts and extends their applications in biosensors and environmental monitoring.