Process Biochemistry, Vol.47, No.12, 2480-2486, 2012
Electro-enzymatic degradation of carbofuran with the graphene oxide-Fe3O4-hemoglobin composite in an electrochemical reactor
In this paper, the degradation of carbofuran with graphene oxide-ferroferric oxide-hemoglobin (GO-Fe3O4-Hb) composite in an electrochemical-enzyme system was reported. The graphene oxide-Fe3O4-hemoglobin composite was fabricated by a two-step process. First, graphene oxide-Fe3O4 (GO-Fe3O4) composite was prepared via a simple and effective chemical precipitation method. Then, hemoglobin was covalently immobilized onto the graphene oxide-Fe3O4 by glutaraldehyde (GA). The GO-Fe3O4-Hb composite showed improved enzyme thermal stability and wider active pH range compared with Fe3O4-Hb and soluble Hb. Furthermore, the GO-Fe3O4-Hb composite can be easily separated under a magnetic field from the reaction solution and reused. To evaluate the electro-enzymatic degradation of carbofuran, electrolytic experiments were carried out with 1 U/mL GO-Fe3O4-Hb composite at 0.007 A, and oxygen flow rate 25 mL/min. Under the optimum conditions by the electrogeneration of hydrogen peroxide (H2O2), the removal efficiency of carbofuran reached 94.6%. Compared with electrochemical and biochemical methods, the removal of carbofuran through electroenzymatic method was comparatively favorable. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords:Graphene oxide;Magnetic microsphere;Hemoglobin;Immobilization;Carbofuran;Electro-enzymatic process