Hydrogen peroxide (H₂O₂) is an important molecular messenger for cellular signal transduction. The capability of direct probing of H₂O₂ in complex biological systems can offer potential for elucidating its manifold roles in living systems. Here we report the fabrication of three-dimensional (3D) WS₂ nanosheet networks with flower-like morphologies on a variety of conducting substrates. The semiconducting WS₂ nanosheets with largely exposed edge sites on flexible carbon fibers enable abundant catalytically active sites, excellent charge transfer, and high permeability to chemicals and biomaterials. Thus, the 3D WS₂-based nano-bio-interface exhibits a wide detection range, high sensitivity and rapid response time for H₂O₂, and is capable of visualizing endogenous H₂O₂ produced in living RAW 264.7 macrophage cells and neurons. First-principles calculations further demonstrate that the enhanced sensitivity of probing H₂O₂ is attributed to the efficient and spontaneous H₂O₂ adsorption on WS₂ nanosheet edge sites. The combined features of 3D WS₂ nanosheet networks suggest attractive new opportunities for exploring the physiological roles of reactive oxygen species like H₂O₂ in living systems.

中文翻译：

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产生用于细胞信号传递的H ₂ O ₂ 的三维WS ₂纳米片状网络†

过氧化氢（H ₂ O ₂）是细胞信号转导的重要分子信使。在复杂的生物系统中直接探测H ₂ O ₂的能力可为阐明其在生物系统中的多种作用提供潜力。在这里，我们报告在各种导电基材上制作具有花朵状形态的三维（3D）WS ₂纳米片网络。WS ₂纳米半导体片在柔性碳纤维上具有大量暴露的边缘位点，可实现丰富的催化活性位点，出色的电荷转移以及对化学物质和生物材料的高渗透性。因此，3D WS ₂基于纳米的生物界面对H ₂ O _2的检测范围广，灵敏度高且响应时间快，并且能够可视化在活RAW 264.7巨噬细胞和神经元中产生的内源性H ₂ O ₂。第一性原理计算进一步证明，探测H ₂ O _2的灵敏度提高归因于WS ₂纳米片边缘位点上有效且自发的H ₂ O ₂吸附。3D WS ₂纳米片网络的综合特征为探索活性氧（如H _2）的生理作用提供了诱人的新机会生命系统中的O ₂。