A novel amperometric hydrogen peroxide biosensor based on immobilized Hb in Pluronic P123-nanographene platelets composite

In this paper, an amperometric biosensor of hydrogen peroxide (H2O2) was fabricated by immobilization of Hemoglobin (Hb) on a Pluronic P123-nanographene platelet (NGP) composite. Direct electron transfer in the Hb-immobilized P123-NGP composite film was greatly facilitated. The surface concentration (Gamma*) and apparent heterogeneous electron transfer rate constant (k(s)) were calculated to be (1.60 +/- 0.17) x 10(-10) mol cm(-2) and 48.51 s(-1), respectively. In addition, the Hb/Pluronic P123-NGP composite showed excellent bioelectrocatalytic activity toward the reduction of H2O2. The biosensor of H2O2 exhibited a linear response to H2O2 in the range of 10-150 mu M and a detection limit of 8.24 mu M (S/N = 3) was obtained. The apparent Michaelis-Menten constant (K-m(app)) was 45.35 mu M. The resulting biosensor showed fast amperometric response, with very high sensitivity, reliability and effectiveness. (C) 2011 Elsevier B.V. All rights reserved.BiophysicsChemistry, PhysicalMaterials Science, BiomaterialsSCI(E)18ARTICLE2427-4328