Sensing of flow and shear stress using fluorescent molecular rotors
Sensing of flow and shear stress using fluorescent molecular rotors
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DOI：
10.1166/sl.2005.003
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发表时间：
2005-03-01
期刊：
影响因子：
--
通讯作者：
Theodorakis, EA
中科院分区：
文献类型：
--
作者：
Haidekker, MA;Akers, W;Theodorakis, EA
分子旋转体是具有两条相互竞争的去激发路径的荧光分子：它们通过荧光或非辐射分子内旋转从激发的单重态返回到基态。分子转子被称为粘度传感器，因为分子内的旋转速度取决于溶剂的粘度。在这项研究中，我们描述了一种新的观察结果，即某些带有亲水头部基团的分子转子在剪切作用下在流体中的发射强度增加。这种强度的增加取决于流体的速度和粘度。当流体速度低至0.6 mm/S时，观察到显著的强度增强。测量剪切流体中分子转子的发射强度可能会导致新的剪切场传感器的开发，从而在不干扰流体的情况下实时测量剪切和流动。
Molecular rotors are fluorescent molecules with two competing pathways of deexcitation: They return from the excited singlet state to the ground state either through fluorescence or through nonradiative intramolecular rotation. Molecular rotors are known as viscosity sensors, because intramolecular rotation rate depends on the viscosity of the solvent. In this study, we describe a new observation that the emission intensity of certain molecular rotors with hydrophilic head groups is elevated in fluids under shear. This intensity increase is dependent on both fluid velocity and viscosity. Statistically significant intensity increase was observed at fluid velocities as low as 0.6 mm/s. Using fiberoptics, local flow profiles could be probed. Measuring emission intensity of molecular rotors in sheared fluids may lead to the development of new shear field sensors, allowing real-time measurement of shear and flow without disturbing the fluid.