College of Chemistry and Chemical Engineering, Jiangxi Normal University, 99 Ziyang Road, Nanchang 330022, P. R. China.
Department of Visual Communication, Shanghai Institute of Technology, 120 Caobao Road, Shanghai 200235, P. R. China.
Anal Methods. 2021 Dec 24;14(1):44-51. doi: 10.1039/d1ay01747k.
Nitroaromatic explosives pose a great threat to the environment and human safety. It is very important to design simple, highly efficient and multifunctional sensors for detecting nitroaromatic explosives. However, a few sensors can determine multicomponent nitroaromatic explosives simultaneously. Eu functionalized MOF-253 (Eu@MOF-253) hybrid material was synthesized using the post-synthetic modification method. The introduction of Eu in MOF-253 caused the fluorescence peak of the ligand to show a distinct red-shift due to its polarization enhancement effect in the presence of 2,4-DNP. The emission and excitation spectra of the Eu@MOF-253 sensor showed overlap with the ultraviolet-visible (UV-vis) absorption spectra of the representative nitroaromatic explosives 2,4-dinitrophenol (2,4-DNP) and 2,4,6-trinitrophenol (TNP). Therefore, it is feasible to discriminate and quantify TNP and 2,4-DNP simultaneously. As proposed, the Eu@MOF-253 luminescent sensor was highly sensitive and selective towards TNP and 2,4-DNP. The other coexisting nitroaromatic explosives did not interfere with the determination. Upon addition of TNP, the fluorescence of the Eu@MOF-253 sensor decreased dramatically and showed an excellent quenching constant () of 1.58 × 10. The fluorescence intensities of the Eu@MOF-253 sensor presented good linear relationships with concentrations of TNP and 2,4-DNP ranging from 0.01-100 μM and 0.01-25 μM, respectively. Low limits of detection (LOD) for both 2,4-DNP and TNP were approximately 10 nM. The determination mechanism is mainly ascribed to the internal filtration effect (IFE) and electron transfer. This work provides a practical method for the highly efficient determination of nitroaromatic explosives.
硝胺炸药对环境和人类安全构成了巨大威胁。设计用于检测硝胺炸药的简单、高效且多功能传感器非常重要。然而，很少有传感器能够同时确定多组分硝胺炸药。采用后合成修饰法合成了 Eu 功能化 MOF-253（Eu@MOF-253）杂化材料。由于极化增强效应，Eu 的引入使配体的荧光峰发生明显红移，在存在 2,4-DNP 的情况下。Eu@MOF-253 传感器的发射和激发光谱与代表性硝胺炸药 2,4-二硝基苯酚（2,4-DNP）和 2,4,6-三硝基苯酚（TNP）的紫外-可见（UV-vis）吸收光谱重叠。因此，同时区分和定量 TNP 和 2,4-DNP 是可行的。正如所提出的，Eu@MOF-253 发光传感器对 TNP 和 2,4-DNP 具有高度的灵敏性和选择性。其他共存的硝胺炸药不会干扰测定。当添加 TNP 时，Eu@MOF-253 传感器的荧光急剧降低，并表现出优异的猝灭常数（）为 1.58×10。Eu@MOF-253 传感器的荧光强度与 TNP 和 2,4-DNP 的浓度呈良好的线性关系，范围分别为 0.01-100 μM 和 0.01-25 μM。对于 2,4-DNP 和 TNP，检测限（LOD）均约为 10 nM。该测定机制主要归因于内滤效应（IFE）和电子转移。这项工作为高效检测硝胺炸药提供了一种实用的方法。
