Microscale, Real-Time Mechanosensors Based on Fluorescent Molecular Rotors

University Of Georgia Research Foundation Inc, Athens GA

Investigators

Abstract

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.