Direct observation of molecular recognition mediated by triple hydrogen bonds at a water/oil interface: time-resolved total internal reflection fluorometry study.
Direct observation of molecular recognition mediated by triple hydrogen bonds at a water/oil interface: time-resolved total internal reflection fluorometry study.
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DOI：
10.1021/ac034839j
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发表时间：
2003-10
影响因子：
7.4
通讯作者：
S. Ishizaka;S. Kinoshita;Y. Nishijima;N. Kitamura
中科院分区：
文献类型：
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作者：
S. Ishizaka;S. Kinoshita;Y. Nishijima;N. Kitamura
用时间分辨全内反射(TIR)荧光光谱直接研究了水/CCl(4)界面上氢键相互作用所介导的分子识别。核黄素(Rf)在CCl(4)相中无客体时的TIR荧光衰变曲线可用单指数函数进行拟合。在N，N-二十八基-[1，3，5]三嗪-2，4，6-三胺(DTT)存在下，CCl(4)相的荧光衰减曲线符合双指数函数，相应的幅度(A(I))随DTT浓度的变化而变化。此外，由荧光动力学各向异性测定，在没有DTT的情况下，RF在界面处的旋转重定向时间为210ps，而在DTT的存在下，观察到快速(160-220ps)和缓慢(670-750ps)的旋转重定向时间。这一缓慢的旋转重定向时间归因于在水/CCl(4)界面形成的RF-DDT络合物。这些结果表明，在TIR条件下，荧光动力学和荧光动力学各向异性测量直接观察到了互补氢键介导的分子识别在水/CCl(4)界面上的有效发生。
Molecular recognition mediated by hydrogen-bonding interactions at a water/CCl(4) interface was investigated directly by means of time-resolved total internal reflection (TIR) fluorescence spectroscopy. The TIR fluorescence decay profile of riboflavin (RF) in the absence of a guest in the CCl(4) phase was fitted satisfactorily by a single-exponential function. In the presence of N,N-dioctadecyl-[1,3,5]triazine-2,4,6-triamine (DTT) as a guest in the CCl(4) phase, on the other hand, the fluorescence decay profiles were best fitted by double-exponential functions with the relevant amplitude (A(i)) being varied with the concentration of DTT. Furthermore, the rotational reorientation time of RF at the interface determined by fluorescence dynamic anisotropy was 210 ps in the absence of DTT, while fast (160-220 ps) and slow (670-750 ps) rotational reorientation times were observed in the presence of DTT. This slow rotational reorientation time was shown to ascribe to that of the RF-DDT complex formed at the water/CCl(4) interface. These results indicate that molecular recognition mediated by complementary hydrogen bonding takes place effectively at the water/CCl(4) interface, which was observed directly by both fluorescence dynamics and fluorescence dynamic anisotropy measurements under the TIR conditions.