Acta Chimica Sinica ›› 2014, Vol. 72 ›› Issue (5): 563-568.DOI: 10.6023/A14030201 Previous Articles     Next Articles



李西平, 刘斯佳, 吴战, 蒋健晖   

  1. 湖南大学化学化工学院化学生物传感与计量学国家重点实验室 长沙 410082
  • 投稿日期:2014-03-20 发布日期:2014-04-25
  • 通讯作者: 蒋健晖
  • 基金资助:

    项目受国家自然科学基金(Nos. 21025521,21221003)和中央高校基本科研业务费(No. 531107040687)资助.

A Novel Approach to Detect 2,4,6-trinitrotoluene/2,4,6-trinitrophenol Based on Fluorescence Quenching via Charge Transfer of Silicon Quantum Dots

Li Xiping, Liu Sijia, Wu Zhan, Jiang Jianhui   

  1. State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082
  • Received:2014-03-20 Published:2014-04-25
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21025521, 21221003) and the Fundamental Research Funds for the Central University (No. 531107040687).

Due to the significant detrimental effects of nitroaromatic explosive on the environment and human health, sensitive, rapid, on-site and simple detection methods for explosives are in high demand. A novel label-free silicon quantum dots (SiQDs)-based sensor is designed for ultrasensitive detection of 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitrophenol (TNP). In this work, amino-functionalized SiQDs are obtained through treating the SiQDs with (3-aminopropyl)triethoxysilane (APTES). The amine-coated SiQDs are not only water-stable but also highly luminescent. Based on the dramatic and selective fluorescence quenching of the amine-coated SiQDs due to charge transfer that resulting from the formation of stable Meisenheimer complexes between electron-deficient TNT/TNP and electron-rich primary amine on the surface of SiQDs, an instant and sensitive sensor is developed for the detection of TNT/TNP which is able to not only directly suppress the fluorescent emission intensity of SiQDs but also induce SiQDs aggregation to result in self-quenching of SiQDs. The results reveal that the developed sensor has high sensitivity for the detection of TNT/TNP. As indicated in experimental results, the fluorescence intensity is proportional to the concentration of TNT/TNP. Meanwhile, linear correlations are obtained respectively for the fluorescence signals to the logarithmic TNT and TNP concentration with 6 and 7 order of range and the detection limit of TNT and TNP is 50 pg/mL for TNT and 5 pg/mL for TNP. Further experiments demonstrate that this analytical method is not susceptible to pH and prevent interference from other nitroaromatics or cationic ions. This simple and cost-effective sensor can be used to detect ultra-trace TNT/TNP in groundwater or seawater. Additionally, this sensor strategy may provide a convenient, rapid, highly sensitive and selective assay platform for nitroaromatic explosive.

Key words: silicon quantum dots (SiQDs), charge transfer, fluorescence quenching, explosives