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 (Γ) and apparent heterogeneous electron transfer rate constant (ks) were calculated to be (1.60±0.17)×10-10molcm-2 and 48.51s-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 10-150μM and a detection limit of 8.24μM (S/N=3) was obtained. The apparent Michaelis-Menten constant (Kmapp) was 45.35μM. The resulting biosensor showed fast amperometric response, with very high sensitivity, reliability and effectiveness.
- Direct electron transfer
- Nanographene platelets