Guo Xin-Ran, Guo Yan-Xin, Chen Juan, Chen Xin-Yue
Institute of Pharmaceutical Analysis, School of Pharmacy, Lanzhou University, Lanzhou 730030, China.
Institute of Pharmaceutical Analysis, School of Pharmacy, Lanzhou University, Lanzhou 730030, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Mar 15;329:125586. doi: 10.1016/j.saa.2024.125586. Epub 2024 Dec 10.
In this work, a simple and sensitive ratiometric fluorescence probe to detect isoniazid (INH) was developed on the basis of carbon dots and MnO nanosheets (MnO NS). Nitrogen-doped carbon dots (FMT-CDs) were synthesized by microwave method using formononetin (FMT) in ammonia water. The oxidase-like activity of MnO NS was utilized to oxidize non-fluorescent o-phenylenediamine (OPD) to 2, 3-diaminophenazine (DAP) with orange fluorescence. It was demonstrated that DAP could effectively quench the fluorescence of FMT-CDs through the inner filtering effect (IFE). Due to the reducing nature of INH, MnO NS was decomposed and thus lost its oxidase-like activity after the addition of INH. Therefore, the production of DAP was reduced, and the fluorescence intensity was decreased, while IFE on FMT-CDs was weakened and the fluorescence of FMT-CDs was recovered. Based on the above principle, a sensitive method for the detection of INH was established based on the fluorescence intensity ratio of the two fluorescent substances, FMT-CDs and DAP, and was successfully applied to the detection of INH in human urine samples. The limit of detection (LOD) could reach to 0.16 μM in human urine samples.
在这项工作中，基于碳点和MnO纳米片（MnO NS）开发了一种简单且灵敏的比色荧光探针用于检测异烟肼（INH）。采用对羟基桂皮素（FMT）在氨水中通过微波法合成了氮掺杂碳点（FMT-CDs）。利用MnO NS的类氧化酶活性将无荧光的邻苯二胺（OPD）氧化为具有橙色荧光的2,3-二氨基吩嗪（DAP）。结果表明，DAP可通过内滤效应（IFE）有效猝灭FMT-CDs的荧光。由于INH具有还原性，加入INH后MnO NS分解，从而失去其类氧化酶活性。因此，DAP的生成减少，荧光强度降低，同时FMT-CDs上的IFE减弱，FMT-CDs的荧光得以恢复。基于上述原理，建立了一种基于FMT-CDs和DAP两种荧光物质荧光强度比检测INH的灵敏方法，并成功应用于人体尿液样本中INH的检测。在人体尿液样本中，检测限（LOD）可达0.16 μM。
