A type I nitroreductase-mimicking nanocatalyst based on 2H–MoS₂/Co₃O₄ nanohybrids for trace nitroaromatic compounds detection is reported in this work. For the preparation of nanocatalyst, ultrathin Co₃O₄ nanoflakes array was in-situ grown onto 2H–MoS₂ nanosheets forming three-dimensional (3D) nanohybrid with large specific surface area as well as abundant active sites. The as-prepared nanocatalyst shows a specific affinity as well as high catalytic activity towards nitroaromatic compounds. Given the favorable nitroreductase-mimicking catalytic activity of 2H–MoS₂/Co₃O₄ nanohybrid, a sensitive and efficient electrochemical microsensor has been constructed for the detection of 2, 4, 6-trinitrotoluene (TNT). Under optimized conditions, the microsensor displayed sensitive response from μM to pM levels with a limit of detection (LOD) of 1 pM. We further employed photoelectron spectroscopy (XPS) analysis and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method to identify the nitroreductase-mimicking mechanism of 2H–MoS₂/Co₃O₄ nanohybrids towards 2, 4, 6- TNT. It was found that the abundant oxygen vacancies in ultrathin Co₃O₄ nanoflakes played an essential role in determining its catalytic performance. Moreover, the developed MoS₂/Co₃O₄ nanozyme has a lower Michaelis-Menten constant (k_m) than that of nature nitroreductase demonstrating a good enzymatic affinity towards its substrates, and further generating a high catalytic activity. This research not only proposed a new type of nanozyme, but also developed a portable electrochemical microsensor for the detection of 2, 4, 6-TNT.

本文报道了一种基于 2H–MoS ₂ /Co ₃ O ₄纳米杂化物的 I 型硝基还原酶模拟纳米催化剂，用于痕量硝基芳族化合物的检测。为了制备纳米催化剂，将超薄Co ₃ O ₄纳米片阵列原位生长在2H-MoS ₂纳米片上，形成具有大比表面积和丰富活性位点的三维（3D）纳米杂化物。所制备的纳米催化剂对硝基芳族化合物显示出特定的亲和力和高催化活性。鉴于 2H–MoS ₂ /Co ₃ O _{4具有良好的硝基还原酶模拟催化活性}nanohybrid 是一种灵敏高效的电化学微传感器，用于检测 2, 4, 6-三硝基甲苯 (TNT)。在优化条件下，微传感器显示出从 μM 到 pM 水平的灵敏响应，检测限 (LOD) 为 1 pM。我们进一步采用光电子能谱 (XPS) 分析和高效液相色谱串联质谱 (HPLC-MS/MS) 方法来确定 2H-MoS ₂ /Co ₃ O ₄纳米杂化物对 2, 4, 6的硝基还原酶模拟机制- TNT。发现超薄Co ₃ O ₄纳米薄片中丰富的氧空位在决定其催化性能方面起着至关重要的作用。此外，开发的 MoS ₂/Co ₃ O ₄纳米酶具有比天然硝基还原酶更低的米氏常数（k _m），表明对其底物具有良好的酶亲和力，并进一步产生高催化活性。该研究不仅提出了一种新型的纳米酶，还开发了一种用于检测2、4、6-TNT的便携式电化学微传感器。