Mapping microscopic viscosity and temperature using molecular rotors

Session

Using FLIM and FCS to Determine Interactions and Dynamics

Authors

Prof Marina Kuimova (1)

Affiliations

1. Imperial College London

Keywords

FLIM, molecular rotors, microviscosity 

Abstract text

Viscosity is one of the main factors which influence diffusion in condensed media. In a cell viscosity can play a role in several diffusion mediated processes, such as drug delivery, signalling and mass transport. Previously, alterations in viscosity in cells and organs have been linked to malfunction; however, mapping viscosity on a single-cell scale remains a challenge. 

We have imaged viscosity and crowding inside lipid mono- and bi-layers, in cells and in vivo using fluorescent probes, called molecular rotors.[1, 2] In molecular rotors the speed of rotation about a sterically hindered bond is viscosity-dependent, which strongly affects fluorescence lifetime or spectra of rotors, allowing fluorescence imaging. This approach enabled us to measure both the microscopic viscosity and temperature [2, 3] as well as the presence of unusual DNA topologies, G-quadruplexes,[4-5] and monitor their temporal changes in real time. The talk will cover our recent developments of this technique, such as genetic and passive targeting of rotors and applications to monitoring disease.

 

References

1) M. K. Kuimova, Phys Chem Chem Phys, 2012, 14, 12671 

2) A. Vyšniauskas et al, Int. Rev. Phys. Chem. 2018, 37:2, 259

3) A. Vyšniauskas, et al, Chem. Sci., 2015, 6, 5773

4) A. Shivalingam, et al Nat. Commun., 2015, 6, 8178

5) P. A. Summers, B. W. Lewis, et al Nat. Commun. 2021, 12, 162