▎ 摘　　要

This paper described an ingenious approach for the fabrication of a promising biosensor, hemoglobin (Hb)/chitosan (Chit)-ionic liquid (IL)-ferrocene (Fc)/graphene (Gr)/glassy carbon electrode (GCE), that exploited the synergistic beneficial characteristics of Fc, Gr and IL for Hb. The proposed biosensor showed a strong electrocatalytic activity toward the reduction of H2O2, which could be attributed to the favored orientation of Hb in the well-confined surface as well as the high electrical conductivity of the resulting Chit-IL-Fc/Gr inorganic hybrid composite. The developed biosensor exhibited a fast amperometric response (2 s), a good linear response toward H2O2 over a wide range of concentration from 50 mu M to 1200 mu M, and a low detection limit of 3.8 mu M. The apparent Michaelis-Menten constant (K-m) of Hb on the composite medium was 0.16 mM, showing high bioelectrocatalytic activity of immobilized protein toward H2O2 reduction. High sensitivity and stability, technically simple and possibility of preparation at short period of time are of great advantages of the developed biosensors. (c) 2012 Elsevier Ltd. All rights reserved.