▎ 摘　　要

For the construction of a mediator-free biosensor, hollow BiOBr microspheres (H-BiOBr MS) were hydrothermally synthesized and combined with reduced graphene oxide (H-BiOBr/rGO hybrids); then, the hybrids were applied to immobilize hemoglobin (Hb) on the surface of a glassy carbon electrode. The structure and morphology of the H-BiOBr MS and H-BiOBr/rGO hybrids were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electronic microscopy (TEM). The experimental results demonstrate that the hollow H-BiOBr/rGO hybrid material has a larger specific surface area and better biocompatibility, which is beneficial for immobilization of hemoglobin (Hb) and furthermore allows proteins to become more stable and bioactive. In addition, the as-prepared modified electrode hybrids can improve effectively the direct electron transfer of Hb. As a result, the hollow BiOBr/rGO microspheres-based H2O2 biosensors exhibit a wide linear range of 0.1 to 420 mu M and extremely low limit of detection 0.02 mu M. The drafted biosensor holds 93.7% of the preliminary feedback to H2O2 after 60-day storage. It is concluded that the mediator-free biosensors containing hollow BiOBr/rGO microspheres have wide applications in biomedicine and environmental analysis.