Using a dual-emission Sm(iii)-macrocycle as the perceptive lab-on-a-molecule chemosensor toward selective and discriminative detection of nitroaromatic explosives

Abstract

Nowadays, it is still a considerable challenge to design an available chemosensor and analytical method for the urgent needs of nitroaromatic explosive detection. Herein, a lab-on-a-molecule chemosensor based on the dual-emission Sm(III)-macrocycle Sm-2_l is designed and used for the discrimination and determination of various nitroaromatic explosives, even in trace amounts. The Sm-2_l-explosive sensing principle is based on different charge transfers, resulting in obvious fluorescence quenching for TNT and 2-NP together with jagged fluorescence signals for other ones. By use of the PCA method, these fluorescence sensing signals are converted into unique fingerprint patterns, which can be easily used to distinguish most explosives from their analogues, even in natural water samples. Sm-2_l also can determine different concentrations of explosives, and its LOD values are 2.1 μM and 3.4 μM for TNP and 2-NP, respectively. Moreover, Sm-2_l also shows satisfactory discrimination abilities for serial mixtures of two explosive analogues, such as 3-NP/4-NP, 2,4-DNT/TNT, TNT/TNP and RDX/DMNB. Overall, our proposed fluorescence chemosensor and analysis method are successful for selective and discriminative detection of nitroaromatic explosives and valuable references for the detection of lanthanide-based materials and multianalytes.