Microscale, Real-Time Mechanosensors Based on Fluorescent Molecular Rotors

分子转子是荧光分子，对溶剂具有不同的敏感性。的粘度和-如最近发现的PI？s实验室-对溶剂？s剪应力。因此，分子转子是超快实时、高分辨率的流体机械传感器。 该研究的总体目标是探索分子转子中机械敏感性的机制，并开发测量技术和仪器。提出了三个目标：1）开发新的比率转子染料系统，以消除流体和仪器的影响，并共价键合到光纤或玻璃表面的新的转子。将转子连接到光纤的尖端是迈向用于流体表征的固态机械传感器的第一步。2）表征新转子在不同粘度和剪切应力状态下的物理特性。这使得能够建立粘度、剪切应力、强度和激发寿命之间的关系，并理解转子的新型剪切敏感机制。3）在流动通道中使用荧光成像来获得流体剪切应力模式，并将其与计算的流体动力学模型进行比较。分子转子有望提供新的高速、高精度、在微观尺度上进行粘度和流动/剪切应力测量的高分辨率方法，允许通过实时荧光测量来取代耗时且容易出错的机械本体粘度测量。 微流体和微血管研究都将受益于分子大小的机械传感器。 该项目包括一个强有力的教育组成部分，并向代表性不足的群体开展外联活动。 调查人员有培训妇女和少数民族的记录。 学生将由Haidekker博士和Theodorakis博士共同指导，并在合成化学和生物工程之间的界面接受跨学科的研究教育。

Molecular rotors are fluorescent molecules with distinct sensitivity towards the solvent?s viscosity and - as recently discovered in the PI?s lab - towards the solvent?s shear stress. Therefore, molecular rotors are ultrafast real-time, high-resolution fluid mechanosensors. The overall goal of the proposed research is to explore the mechanisms of mechanosensitivity in molecular rotors, and to develop measurement techniques and instrumentation. Three goals are proposed:1) To develop new ratiometric rotor-dye systems to eliminate fluid and instrument influences, and to covalently bind the new rotors to optical fibers or glass surfaces. Rotors attached to the tip of a fiber are the first step towards a solid-state mechanosensor for fluid characterization.2) To characterize the photophysical properties of new rotors under different viscosity and shear stress regimes. This allows to establish a relationship between viscosity, shear stress, intensity and excited lifetime and understand the novel shear-sensitive mechanism of the rotors.3) To use fluorescent imaging in flow channels to acquire fluid shear stress patterns and compare those to computed fluid dynamic models.Molecular rotors promise to provide a new high-speed, high-accuracy, high-resolution approach to viscosity and flow/shear stress measurement on a microscopic scale, allowing to replace time-consuming and error-prone mechanical bulk viscosity measurements by real-time fluorescence measurements. Both microfluidics and microvascular research will benefit from a molecular-sized mechanosensor. The project includes a strong educational component and outreach to underrepresented groups. The investigators have a track record of training women and minorities. Students will be co-mentored by Dr. Haidekker and Dr. Theodorakis and receive interdisciplinary research education at the interface between synthetic chemistry and bioengineering.