Single-molecule detection of a fluorescent nucleobase analog via multiphoton excitation

Nobis, D., Fisher, R. S., Simmermacher, M., Hopkins, P. A., Tor, Y., Jones, A. C. and Magennis, S. W. (2019) Single-molecule detection of a fluorescent nucleobase analog via multiphoton excitation. Journal of Physical Chemistry Letters, 10(17), pp. 5008-5012. (doi: 10.1021/acs.jpclett.9b02108) (PMID:31397575)

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Abstract

The ability to routinely detect fluorescent nucleobase analogues at the single-molecule level would create a wealth of opportunities to study nucleic acids. We report the multiphoton-induced fluorescence and single-molecule detection of a dimethylamine-substituted extended-6-aza-uridine (DMAthaU). We show that DMAthaU can exist in a highly fluorescent form, emitting strongly in the visible region (470–560 nm). Using pulse-shaped broadband Ti:sapphire laser excitation, DMAthaU undergoes two-photon (2P) absorption at low excitation powers, switching to three-photon (3P) absorption at high incident intensity. The assignment of a 3P process is supported by cubic response calculations. Under both 2P and 3P excitation, the single-molecule brightness was over an order of magnitude higher than reported previously for any fluorescent base analogue, which facilitated the first single-molecule detection of an emissive nucleoside with multiphoton excitation.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Magennis, Dr Steven and Nobis, Mr David
Authors: Nobis, D., Fisher, R. S., Simmermacher, M., Hopkins, P. A., Tor, Y., Jones, A. C., and Magennis, S. W.
College/School:College of Science and Engineering > School of Chemistry
Journal Name:Journal of Physical Chemistry Letters
Publisher:American Chemical Society
ISSN:1948-7185
ISSN (Online):1948-7185
Published Online:09 August 2019
Copyright Holders:Copyright © 2019 American Chemical Society
First Published:First published in Journal of Physical Chemistry Letters 10(17):5008-501
Publisher Policy:Reproduced in accordance with the publisher copyright policy

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