In this paper, we reported the synthesis of MnCO3-Au hybrid microspheres and their application on the electrochemical biosensing of hydrogen peroxide (H2O2) based on immobilization of hemoglobin (Hb). The characterization of MnCO3-Au microspheres revealed that abundant of Au nanoparticles (AuNPs) have been absorbed on the surface of spherical MnCO3 by the electrostatic assembly. The combined unique properties of MnCO3-Au microspheres are beneficial for the realization of the direct electron transfer of Hb. Hb immobilized on the microspheres maintained its biological activity, showing a surface controlled process with the heterogeneous electron transfer rate constant (ks) of 2.63 s-1. The fabricated biosensor displayed an excellent performance to the electrocatalytic reduction of H2O2. The linear range for the determination of H2O2 was from 0.06 μM to 40.0 μM with a detection limit of 0.015 µM (S/N=3). The biosensor also exhibited high selectivity, good repeatability and long-term stability, which offer great potentials for the H2O2 detection in real sample analysis.

中文翻译：

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将血红蛋白固定在负载有 Au 纳米颗粒的 MnCO3 球上作为对过氧化氢的高效传感平台

在本文中，我们报道了 MnCO3-Au 杂化微球的合成及其在基于固定化血红蛋白 (Hb) 的过氧化氢 (H2O2) 电化学生物传感中的应用。MnCO3-Au微球的表征表明，大量的金纳米粒子（AuNPs）通过静电组装吸附在球形MnCO3表面。MnCO3-Au微球的综合独特性能有利于实现Hb的直接电子转移。固定在微球上的 Hb 保持其生物活性，显示出表面受控过程，异质电子转移速率常数 (ks) 为 2.63 s-1。制备的生物传感器对 H2O2 的电催化还原表现出优异的性能。H2O2 的测定线性范围从 0 开始。06 μM 至 40.0 μM，检测限为 0.015 μM (S/N=3)。该生物传感器还表现出高选择性、良好的重复性和长期稳定性，为实际样品分析中的H2O2检测提供了巨大潜力。