Issue 1, 2017

Electronic tuning of self-healing fluorophores for live-cell and single-molecule imaging

Abstract

Bright, long-lasting organic fluorophores enable a broad range of imaging applications. “Self-healing” fluorophores, in which intra-molecularly linked protective agents quench photo-induced reactive species, exhibit both enhanced photostability and biological compatibility. However, the self-healing strategy has yet to achieve its predicted potential, particularly in the presence of ambient oxygen where live-cell imaging studies must often be performed. To identify key bottlenecks in this technology that can be used to guide further engineering developments, we synthesized a series of Cy5 derivatives linked to the protective agent cyclooctatetraene (COT) and examined the photophysical mechanisms curtailing their performance. The data obtained reveal that the photostability of self-healing fluorophores is limited by reactivity of the COT protective agent. The addition of electron withdrawing substituents to COT reduced its susceptibility to reactions with molecular oxygen and the fluorophore to which it is attached and increased its capacity to participate in triplet energy transfer. Exploiting these insights, we designed and synthesized a suite of modified COT-fluorophores spanning the visible spectrum that exhibited markedly increased intra-molecular photostabilization. Under ambient oxygen conditions, the photostability of Cy3 and Cy5 fluorophore derivatives increased by 3- and 9-fold in vitro and by 2- and 6-fold in living cells, respectively. We further show that this approach can improve a silicon rhodamine fluorophore. These findings offer a clear strategy for achieving the full potential of the self-healing approach and its application to the gamut of fluorophore species commonly used for biomedical imaging.

Graphical abstract: Electronic tuning of self-healing fluorophores for live-cell and single-molecule imaging

Supplementary files

Article information

Article type
Edge Article
Submitted
06 Jul 2016
Accepted
05 Sep 2016
First published
07 Sep 2016
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY-NC license

Chem. Sci., 2017,8, 755-762

Electronic tuning of self-healing fluorophores for live-cell and single-molecule imaging

Q. Zheng, S. Jockusch, Z. Zhou, R. B. Altman, H. Zhao, W. Asher, M. Holsey, S. Mathiasen, P. Geggier, J. A. Javitch and S. C. Blanchard, Chem. Sci., 2017, 8, 755 DOI: 10.1039/C6SC02976K

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements