Jain Puneet, Aida Takuya, Motosuke Masahiro
Department of Mechanical Engineering, Faculty of Engineering, Tokyo University of Science, 6-3-1, Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
Water Frontier Research Center, Research Institute for Science and Technology, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 125-8585, Japan.
Micromachines (Basel). 2021 Sep 15;12(9):1109. doi: 10.3390/mi12091109.
Fluorescence anisotropy, a technique to study the folding state of proteins or affinity of ligands, is used in this present work as a temperature sensor, to measure the microfluidic temperature field, by adding fluorophore in the liquid. Fluorescein was used as a temperature-sensing probe, while glycerol-aq. ammonia solution was used as a working fluid. Fluorescence anisotropy of fluorescein was measured by varying various parameters. Apart from this, a comparison of fluorescence anisotropy and fluorescence intensity is also performed to demonstrate the validity of anisotropy to be applied in a microfluidic field with non-uniform liquid thickness. Viscosity dependence and temperature dependence on the anisotropy are also clarified; the results indicate an appropriate selection of relation between molecule size and viscosity is important to obtain a large temperature coefficient in anisotropy. Furthermore, a practical calibration procedure of the apparatus constant is proposed. In addition, the potential of temperature imaging is confirmed by the measurement of temperature distribution under focused laser heating.
荧光各向异性是一种用于研究蛋白质折叠状态或配体亲和力的技术，在本研究中用作温度传感器，通过在液体中添加荧光团来测量微流控温度场。使用荧光素作为温度传感探针，而甘油 - 氨水用作工作流体。通过改变各种参数来测量荧光素的荧光各向异性。除此之外，还进行了荧光各向异性与荧光强度的比较，以证明各向异性应用于液体厚度不均匀的微流控领域的有效性。还阐明了各向异性对粘度和温度的依赖性；结果表明，适当选择分子大小与粘度之间的关系对于在各向异性中获得较大的温度系数很重要。此外，还提出了仪器常数的实际校准程序。另外，通过测量聚焦激光加热下的温度分布证实了温度成像的潜力。
