Tuning the Sensitivity of Fluorescent Porphyrin Dimers to Viscosity and Temperature.

Aurimas Vyšniauskas,Dong Ding,Marina K Kuimova,Milan Balaz,Harry L Anderson,Maryam Qurashi,Igor Boczarow

doi:10.1002/chem.201700740

Aurimas Vyšniauskas, Dong Ding + Show 5 more

Open Access

https://doi.org/10.1002/chem.201700740

Copy DOI

Abstract

Conjugated porphyrin dimers have emerged as versatile viscosity‐sensitive fluorophores that are suitable for quantitative measurements of microscopic viscosity by ratiometric and fluorescence lifetime‐based methods, in a concentration‐independent manner. Here, we investigate the effect of extended conjugation in a porphyrin‐dimer structure on their ability to sense viscosity and temperature. We show that the sensitivity of the fluorescence lifetime to temperature is a unique property of only a few porphyrin dimers.

Highlights

Microscopic viscosity is an important characteristic of a heterogeneous material and can have wide implications for the macroscopic properties of an object
Molecular rotors are a class of viscosity-sensitive fluorophores that hold great promise for microviscosity measurements, applicable to biological and materials sciences.[1,2]
Fluorescence sensitivity to viscosity in molecular rotors arises from a fluorescent-to“dark” state transition that is linked to a change in the conformation of a fluorophore and is strongly affected by the viscosity of the environment

Summary

Introduction

Microscopic viscosity is an important characteristic of a heterogeneous material and can have wide implications for the macroscopic properties of an object. A particular advantage of molecular rotors over other microviscosity measurement techniques such as fluorescence correlation spectroscopy (FCS),[5,6] fluorescence recovery after photobleaching (FRAP)[7,8] or single particle tracking (SPT)[9,10] is their ability to produce viscosity images within relatively short acquisition times instead of single-point measurements available with most alternative techniques This advantage led to wide-spread use of molecular rotors for dynamic microviscosity measurements in live mammalian and bacterial cells,[4,11,12] as well as in model biological systems.[13,14,15,16]. We examine the ability of the selected dimers to simultaneously measure viscosity and temperature

Results and Discussion

TÞ þ kf ð5Þ

Conclusion

Conflict of interest