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 (H(2)O(2)) 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 (Γ*) and apparent heterogeneous electron transfer rate constant (k(s)) were calculated to be (1.60±0.17)×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 H(2)O(2). The biosensor of H(2)O(2) exhibited a linear response to H(2)O(2) in the range of 10-150 μM and a detection limit of 8.24 μM (S/N=3) was obtained. The apparent Michaelis-Menten constant (K(m)(app)) was 45.35 μM. The resulting biosensor showed fast amperometric response, with very high sensitivity, reliability and effectiveness.