Hydrogen peroxide (H₂O₂) plays an important role in various signal transduction pathways and regulates important cellular processes. However, monitoring and quantitatively assessing the distribution of H₂O₂ molecules inside living cells requires a nanoscale sensor with molecular-level sensitivity. Herein, we show the first demonstration of sub-10 nm-sized fluorescent nanodiamonds (NDs) as catalysts for the decomposition of H₂O₂ and the production of radical intermediates at the nanoscale. Furthermore, the nitrogen-vacancy quantum sensors inside the NDs are employed to quantify the aforementioned radicals. We believe that our method of combining the peroxidase-mimicking activities of the NDs with their intrinsic quantum sensor showcases their application as self-reporting H₂O₂ sensors with molecular-level sensitivity and nanoscale spatial resolution. Given the robustness and the specificity of the sensor, our results promise a new platform for elucidating the role of H₂O₂ at the cellular level.

中文翻译：

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使用自报告荧光纳米金刚石量子传感器检测少量过氧化氢分子

过氧化氢 (H ₂ O ₂ ) 在各种信号转导途径中发挥重要作用并调节重要的细胞过程。然而，监测和定量评估活细胞内H ₂ O ₂分子的分布需要具有分子水平灵敏度的纳米级传感器。在这里，我们首次展示了亚 10 nm 尺寸的荧光纳米金刚石 (NDs) 作为 H ₂ O _{2分解的催化剂}以及纳米级自由基中间体的生产。此外，ND 内部的氮空位量子传感器用于量化上述自由基。我们相信，我们将 ND 的过氧化物酶模拟活性与其固有的量子传感器相结合的方法展示了它们作为具有分子水平灵敏度和纳米级空间分辨率的自我报告 H ₂ O _{2传感器的应用。}鉴于传感器的稳健性和特异性，我们的结果有望为阐明 H ₂ O ₂在细胞水平上的作用提供一个新平台。