Biosensor based on horseradish peroxidase modified carbon nanotubes for determination of 2,4-dichlorophenol

A novel and convenient strategy is presented for determination of 2,4-dichlorophenol (2,4-DCP). Horseradish peroxidase (HRP) was self-assembled on a multiwalled carbon nanotubues (MWNTs) modified glassy carbon (GC) electrode. In the presence of hydrogen peroxide (H2O2), 2,4-DCP can be oxidized at this enzyme electrode and the reduction current is proportional to the concentration of the 2,4-DCP. The method showed good linearly for 1.0 × 10−6–1.0 × 10−4 M 2,4-DCP with a detection limit of 3.8 × 10−7 M under the optimal conditions. The peak current of the HRP-MWNTs-GC electrode decreased by about 15% over two weeks. The mechanism of the enzyme biosensor was also studied, and a kinetic equation was derived. The performance of the electrode was verified by determination of 2,4-DCP in environmental water.