Planar Is Better: Monodisperse Three-Layered MoS2 Quantum Dots as Fluorescent Reporters for 2,4,6-Trinitrotoluene Sensing in Environmental Water and Luggage Cases

作者：Hui Zhu, Hui Zhang, Yunsheng Xia · 发表于：Analytical Chemistry · 年份：2018 · DOI：10.1021/acs.analchem.7b04893 · 被引用次数：64 · 研究领域：Advanced biosensing and bioanalysis techniques、2D Materials and Applications、Luminescence and Fluorescent Materials

In this study, we present a simple but effective fluorescent system for highly sensitive and versatile sensing of 2,4,6-trinitrotoluene (TNT) using few layered planar MoS 2 quantum dots (QDs) as reporters. Excitation-independent emitting MoS 2 QDs were first fabricated by using the proposed ultrasonic–hydrothermal-based top-down method assisted by carbon-free hydroxylamine hydrochloride. The obtained pristine MoS 2 QDs were then modified with cysteine for introducing amino groups as TNT binding sites. The as-prepared MoS 2 QDs possess a planar structure, which can more adequately interact with flat aromatic TNT molecules due to π–π attraction and decreased steric effects, compared with traditional spherical/quasi-spherical QDs. As a result, they exhibit extremely high sensitivity for TNT sensing (1 nM and 2 ng for solution and substrate assay, respectively). The common ions containing in environmental water samples do not interfere with the sensing. Furthermore, the QDs-decorated test paper shows an instantaneous (within 1 min) response to trace amounts of deposited TNT, and the fluorescence quenching can even be well-visualized by the naked eye. Because of favorable analytical performances, the proposed MoS 2 QDs-based TNT sensing system has potential applications in both environmental water monitoring and security screening.