The mechanism of 2,4,6-trinitrotoluene detection with amino acid-capped quantum dots: a density functional theory study
The mechanism of 2,4,6-trinitrotoluene detection with amino acid-capped quantum dots: a density functional theory study
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氨基酸封端量子点检测2,4,6-三硝基甲苯的机理：密度泛函理论研究
DOI：
10.1039/c5ra07088k
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发表时间：
2015-05
期刊：
影响因子：
3.9
通讯作者：
Chen Jun
中科院分区：
文献类型：
--
作者：
Lou Zhaoyang;Cui Yingqi;Yang Mingli;Chen Jun
当氨基酸封端的量子点溶液遇到2，4，6-三硝基甲苯（TNT）时，它从无色变为红色，其荧光被淬灭。这是最近开发的用于检测痕量TNT的技术。然而，是什么导致了颜色和荧光的变化仍然存在争议。采用密度泛函理论计算方法，研究了TNT与半胱氨酸反应产物的结构和光学性质。两个化合物，即，一个迈森海默络合物和TNT阴离子，这是从加成反应和酸碱反应分别得到的，其特征在于，但它们都不能单独用来解释实验结果。我们的计算提出了它们在溶液中共存的可能性，从它们相似的热力学稳定性和预测的吸收和振动光谱。它们的计算的光学吸收光谱的叠加产生的频带分布类似于那些的实验。此外，测量的拉曼光谱，已被用来表征的迈森海默络合物的形成不能排除的TNT阴离子的形成，其特征振动被掩埋的那些前者。计算还表明，在Meisenheimer配合物中，TNT苯环上的电子离域被半胱氨酸所阻断，而对于TNT阴离子，氢原子的去除增强了电子离域，并导致其第一激发相对于Meisenheimer配合物的红移.因此，TNT检测的关键是控制QD的尺寸，以便将它们的发射调节到与TNT和氨基酸形成的迈森海默络合物或TNT阴离子的吸收带周围的波长。
When an amino acid-capped quantum dots solution meets 2,4,6-trinitrotoluene (TNT), it changes from colorless to red and its fluorescence is quenched. This is a recently developed technique for the detection of TNT in trace amounts. However, what causes the changes in coloration and fluorescence remains controversial. Using density functional theory calculations, we studied the structures and optical properties of the products of TNT reacting with cysteine. Two compounds, namely, a Meisenheimer complex and a TNT anion, which are obtained from an addition reaction and an acid–base reaction respectively, were characterized, but neither of them could be used solely to interpret the experimental results. Our calculations proposed the possibility of their coexistence in the solution from their similar thermodynamic stability and their predicted absorption and vibrational spectra. The superposition of their calculated optical absorption spectra produces band distributions similar to those of the experiments. Moreover, the measured Raman spectra that had been used to characterize the formation of the Meisenheimer complex cannot exclude the formation of the TNT anion whose characteristic vibrations are buried by those of the former. Our calculations also revealed that in the Meisenheimer complex the electron delocalization in the phenyl ring of TNT is blocked by the attached cysteine, while for the TNT anion, the removal of the hydrogen atom enhances the electron delocalization and leads to a redshift of its first excitation in comparison with that of the Meisenheimer complex. Therefore, the key to TNT detection is to control the size of the QDs so as to adjust their emission to a wavelength around the absorption bands of either the Meisenheimer complex or the TNT anion that are formed with TNT and the amino acid.
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基于氧化铁磁性纳米颗粒的2,4,6-三硝基甲苯选择性荧光响应和磁分离探针
DOI：
10.1007/s00216-013-6873-6
发表时间：
2013-03
期刊：
Anal. Bioanal.Chem.
影响因子：
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作者：
Feng Wang;Qun Shao;Jun Zhang;Jin Liu
通讯作者：
Jin Liu
影响因子：
6.1
作者：
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通讯作者：
E. M. A. Ali;H. Edwards;I. Scowen
影响因子：
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作者：
van Dillewijn, Pieter;Couselo, Jose L.;Ramos, Juan L.
通讯作者：
Ramos, Juan L.
影响因子：
4.4
作者：
BECKE, AD
通讯作者：
BECKE, AD
磁性室温磷光多功能纳米复合材料作为化学传感器用于检测和光驱动酶模拟物用于降解 2,4,6-三硝基甲苯
影响因子：
--
作者：
Zou, Wen-Sheng;Yang, Jing;Yang, Ting-Ting;Hu, Xin;Lian, Hong-Zhen
通讯作者：
Lian, Hong-Zhen