title: On the Mechanisms of Cyanine Fluorophore Photostabilization.
abstract: Cyanine fluorophores exhibit greatly improved photostability when covalently linked to stabilizers, such as cyclooctatetraene (COT), nitrobenzyl alcohol (NBA) or Trolox. However, the mechanism by which photostabilization is mediated has yet to be determined. Here we present spectroscopic evidence that COT, when covalently linked to Cy5, substantially reduces the lifetime of the Cy5 triplet state, and that the degree of triplet state quenching correlates with enhancements in photostability observed in single-molecule fluorescence measurements. By contrast, NBA and Trolox did not quench the Cy5 triplet state under our conditions suggesting that their mechanism of photostabilization is different from COT and does not target the fluorophore triplet state directly. These findings provide insights into the mechanisms of fluorophore photostabilization that may lead to improved fluorophore designs for biological imaging applications.
authors.affiliation: Department of Physiology and Biophysics, Weill Medical College of Cornell University, 1300 York Avenue, New York, New York 10065, United States ; Tri-Institutional Training Program in Chemical Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, New York 10065, United States.
authors.forename: Qinsi
authors.initials: Q
authors.lastname: Zheng
authors.forename: Steffen
authors.initials: S
authors.lastname: Jockusch
authors.forename: Zhou
authors.initials: Z
authors.lastname: Zhou
authors.forename: Roger B
authors.initials: RB
authors.lastname: Altman
authors.forename: J David
authors.initials: JD
authors.lastname: Warren
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Turro
authors.forename: Scott C
authors.initials: SC
authors.lastname: Blanchard