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In this paper, the hemoglobin (Hb)-collagen microbelt modified electrode with three-dimensional configuration was fabricated via the electrospinning method. Direct electron transfer of the Hb immobilized into the electrospun collagen microbelts was greatly facilitated. The apparent heterogeneous electron transfer rate constant (ks) was calculated to be 270.6s-1. The electrospun Hb-collagen microbelt modified electrode showed an excellent bioelectrocatalytic activity toward the reduction of H2O2. The amperometric response of the biosensor varied linearly with the H2O2 concentration ranging from 5×10-6molL-1 to 30×10-6molL-1, with a detection limit of 0.37×10-6molL-1 (signal-to-noise ratio of 3). The apparent Michaelis-Menten constant (Kmapp) was 77.7μmolL-1. The established biosensor exhibited fast amperometric response, high sensitivity, good reproducibility and stability. © 2011 Elsevier B.V.

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. © 2011 Elsevier B.V.

TiB2–Cu ceramic–metal composites were prepared by combustion synthesis of elemental titanium, boron, and copper powders. The synthesized product consisted of two phases: TiB2 and copper. The addition of copper improved the strength and fracture toughness, thermal expansion coefficient, and thermal conductivity of TiB2. Thermal shock and ablation resistances of TiB2–Cu composites were studied using a plasma torch arc heater.Monolithic TiB2 failed catastrophically when the plasma arc flow reached the specimen surface. However, no cracks were found on the ablation surface of the TiB2–Cu ceramic–metal composites. The fractional mass loss was 4.09% for a TiB2– 40Cu composite, which was close to the traditionalW/Cu alloys. Volatilization of metal binder and mechanical erosion of TiB2 were observed to be the major ablation mechanisms. An ablation process model is proposed for the TiB2–Cu composites.