A novel hydrogen peroxide biosensor based on hemoglobin immobilized on magnetic chitosan microspheres modified electrode

摘要

A novel magnetic chitosan microsphere (MCMS) was prepared using carbon-coated iron magnetic nanoparticles and chitosan. Hemoglobin (Hb) was successfully immobilized on the surface of MCMS modified glassy carbon electrode (GCE) with the cross-linking of glutaraldehyde, and the immobilized Hb displayed an excellent electrocatalytic property to the reduction of H_2O_2 in the presence of the mediator of methylene blue (MB). The effects of the experimental variables such as the concentration of MB, solution pH and the working potential were investigated for optimum analytical performance using steady-state amperometry. This biosensor had a fast response of H_2O_2 less than 10 s and excellent linear relationships were obtained in the concentration range of 0.069-0.29 mM and 0.29-3.0mM with the detection limit of 0.021 mM (S/N = 3) under the optimum conditions. Moreover, the selectivity, stability and reproducibility of this biosensor were evaluated with satisfactory results.