Triplet-State Investigations of Fluorescent Dyes at Dielectric Interfaces Using Total Internal Reflection Fluorescence Correlation Spectroscopy
2009 (English)In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 113, no 19, 5554-5566 p.Article in journal (Refereed) Published
The triplet-state kinetics of several fluorescent dyes used in ultrasensitive fluorescence microscopy are investigated using total internal reflection fluorescence correlation spectroscopy (TIR-FCS). A theoretical outline of the correlation analysis and the physical aspects of evanescent excitation and fluorescence emission at dielectric interfaces are given. From this analysis, the rates of intersystem crossing and triplet decay are deduced for fluorescein, ATTO 488, rhodamine 110, rhodamine 123, and rhodamine 6G in aqueous buffer solutions. All investigated dyes show slightly higher triplet rates at the dielectric interface compared to bulk solution measurements. We attribute this enhancement to possible modifications of the dyes’ photophysical properties near a dielectric interface. In the case of rhodamine 6G, the impact of changes in the dye concentration, ionic strength of the solvent, and potassium iodide concentration are also investigated. This leads to a better understanding of the influences of dye−dye, dye−solvent, and dye−surface interactions on the increased triplet intersystem crossing and triplet decay rates. The study shows that analysis of triplet-state kinetics by TIR-FCS not only results in a better understanding of how the photophysical properties of the dyes are affected by the presence of an interface, but also provides a means for probing the microenvironment near dielectric interfaces.
Place, publisher, year, edition, pages
Washington, DC: American Chemical Society , 2009. Vol. 113, no 19, 5554-5566 p.
fluorescence correlation spectroscopy, FCS, triplet state, surface effects, TIR, TIR-FCS, total internal reflection
IdentifiersURN: urn:nbn:se:kth:diva-12338DOI: 10.1021/jp8110088ISI: 000265887700010ScopusID: 2-s2.0-66149146666OAI: oai:DiVA.org:kth-12338DiVA: diva2:309782
QC 201102082010-04-122010-04-082012-02-20Bibliographically approved