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 (Γ*) and apparent heterogeneous electron transfer rate constant (ks) 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 H2O2. The biosensor of H2O2 exhibited a linear response to H2O2 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 (Kmapp) was 45.35 μM. The resulting biosensor showed fast amperometric response, with very high sensitivity, reliability and effectiveness.

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► An amperometric biosensor of hydrogen peroxide (H2O2) was substantially facilitated by immobilized Hemoglobin (Hb) in Pluronic P123-nanographene platelets (NGPs) composite.
► The surface concentration (Γ*) and the apparent heterogeneous electron transfer rate constant (ks) were calculated as (1.60 ± 0.17) × 10−10 mol cm−2 and 48.51 s−1, respectively.
► The apparent Michaelis–Menten constant (Kmapp) of the amperometric biosensor for the determination of H2O2 was 45.35 μM, which was markedly smaller than the value in the previous reports.