Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, China.
Anal Chem. 2011 Feb 15;83(4):1401-7. doi: 10.1021/ac1028825. Epub 2011 Jan 24.
In this study, we design a FRET system consisting of gold nanorod (AuNR) and quantum dots (QDs) for turn-on fluorescent sensing of 2,4,6-trinitrotoluene (TNT) in near-infrared region. The amine-terminated AuNR and carboxyl-terminated QDs first form a compact hybrid assembly through amine-carboxyl attractive interaction, which leads to a high-efficiency (>92%) FRET from QDs to AuNRs and an almost complete emission quenching. Next, added TNT molecules break the preformed assembly because they can replace the QDs around AuNRs, based on the specific reaction of forming Meisenheimer complexes between TNT and primary amines. Thus, the FRET is switched off, and a more than 10 times fluorescent enhancement is obtained. The fluorescence turn-on is immediate, and the limit of detection for TNT is as low as 0.1 nM. Importantly, TNT can be well distinguished from its analogues due to their electron deficiency difference. The developed method is successfully applied to TNT sensing in real environmental samples.
在这项研究中，我们设计了一个由金纳米棒（AuNR）和量子点（QDs）组成的 FRET 系统，用于在近红外区域中对 2,4,6-三硝基甲苯（TNT）进行开式荧光感应。胺端 AuNR 和羧基端 QDs 首先通过胺-羧基吸引相互作用形成紧凑的混合组装体，导致从 QDs 到 AuNRs 的高效（>92%）FRET 和几乎完全的发射猝灭。接下来，加入的 TNT 分子由于能够取代 AuNR 周围的 QDs，基于 TNT 和伯胺之间形成 Meisenheimer 配合物的特定反应，破坏了预先形成的组装体。因此，FRET 被关闭，并且获得了超过 10 倍的荧光增强。荧光开启是即时的，TNT 的检测限低至 0.1 nM。重要的是，由于电子缺乏差异，可以很好地区分 TNT 与其类似物。所开发的方法成功地应用于实际环境样品中的 TNT 传感。
