Optimizing enzyme immobilization and biocatalytical activity of a micro-structured biofuel-cell for electricity generation

Abstract

Abstract. Glucose oxidase (GOx) was immobilized on mesoporous carbon (OMC), which was then used to fabricate a novel bio-electrode, aiming at facilitating electron transfer efficiency and minimizing the electrode size. Response surface methodology study on the various factors affecting GOx immobilization on OMC showed that, the maximum GOx adsorption on OMC was 37.38 mg/ g OMC with the activity of 8531.59 U g -1 GOx-immobilized OMC under the optimized conditio. The FTIR analysis showed that GOx immobilized-OMC obtained the typical absorption peaks of amideâ… (1656 cm -1 ) and amideâ…ii¼ˆ1542 cm -1 i¼‰in GOx. The direct electrochemistry and electrocatalysis behavior of GOx on the electrode made with OMC and PEDOT/PSS were characterized by cyclic voltammogram (CV), which indicated that GOx immobilized-OMC displayed direct, reversible and surface-controlled redox reaction with an enhanced electron transfer coefficient (I±) of 0.57 in 10 mM glucose of 0.1 M phosphate buffer solution PBS (pH 7.0). Furthermore, it was also discovered that in the presence of O 2 , GOx immobilized-OMC still processes an excellent bioelectrocatalytic activity for the glucose oxidation with high current density. The GOx immobilized-OMC showed a great potential for the utilization as the anode in micro-scale biofuel cell and electrode in glucose biosensor.