Materials Genome Institute, Shanghai University, Shanghai, 200444, China.
State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China.
Anal Chim Acta. 2022 Aug 15;1221:340078. doi: 10.1016/j.aca.2022.340078. Epub 2022 Jun 23.
A type I nitroreductase-mimicking nanocatalyst based on 2H-MoS/CoO nanohybrids for trace nitroaromatic compounds detection is reported in this work. For the preparation of nanocatalyst, ultrathin CoO nanoflakes array was in-situ grown onto 2H-MoS 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-MoS/CoO 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-MoS/CoO nanohybrids towards 2, 4, 6- TNT. It was found that the abundant oxygen vacancies in ultrathin CoO nanoflakes played an essential role in determining its catalytic performance. Moreover, the developed MoS/CoO nanozyme has a lower Michaelis-Menten constant (k) 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.
本工作报道了一种基于 2H-MoS/CoO 纳米杂化物的 I 型硝基还原酶模拟纳米催化剂，用于痕量硝基芳烃化合物的检测。为了制备纳米催化剂，在 2H-MoS 纳米片上原位生长超薄 CoO 纳米薄片阵列，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烃化合物具有特异亲和力和高催化活性。鉴于 2H-MoS/CoO 纳米杂化物具有良好的硝基还原酶模拟催化活性，构建了一种用于检测 2,4,6-三硝基甲苯（TNT）的灵敏高效电化学微传感器。在优化条件下，该微传感器对 TNT 的检测范围从μM 到 pM 级，检测限（LOD）低至 1 pM。我们进一步采用光电电子能谱（XPS）分析和高效液相色谱串联质谱（HPLC-MS/MS）方法，确定了 2H-MoS/CoO 纳米杂化物对 2,4,6-TNT 的硝基还原酶模拟机制。研究发现，超薄 CoO 纳米薄片中的丰富氧空位在确定其催化性能方面起着至关重要的作用。此外，所开发的 MoS/CoO 纳米酶的米氏常数（k）低于天然硝基还原酶，表明其对底物具有良好的酶亲和力，并进一步产生高催化活性。本研究不仅提出了一种新型纳米酶，还为 2,4,6-TNT 的检测开发了一种便携式电化学微传感器。
