Immobilization of laccase on Fe3O4@MF-CNTs for the rapid and sensitive biosensing of catechol

Rapid and sensitive detection of hazardous compounds is of great importance for sensors. This work presents the immobilization of laccase on Fe3O4@MF-CNTs nanocomposites (Fe3O4@MF-CNTs-lac) for the fast and sensitive detection of catechol. Electrochemical impedance spectroscopy (EIS) results revealed that the combined effect of Fe3O4@MF and carbon nanotubes (CNTs) facilitates electron transfer between laccase and the electrode. Amperometric curves indicated that the Fe3O4@MF-CNTs-Lac biosensor can respond rapidly to a substrate and detect catechol within 0.5 s. The Fe3O4@MF-CNTs-Lac biosensor possesses a low detection limit of 0.84 μM (S/N = 3) with a linear range of 1–3000 μM, as well as high sensitivity, remarkable organic compound tolerance, and good selectivity, reproducibility and stability. The catechol biosensing assays revealed that Fe3O4@MF-CNTs-Lac can be operated in acidic water environments. Most importantly, the Fe3O4@MF-CNTs-Lac biosensor exhibited reliable results in real water sample analysis. The outstanding biosensing performances reveal that the Fe3O4@MF-CNTs-Lac biosensor has a technical application in the treatment of catechol to avoid catechol pollution.