Journal
JOURNAL OF PHYSICAL CHEMISTRY A
Volume 108, Issue 10, Pages 1657-1665Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jp037222e
Keywords
-
Ask authors/readers for more resources
Photobleaching is a severely limiting factor in the optical study of single biomolecules. We investigate the photobleaching of rhodamine 6G (R6G) ensembles in poly(vinyl alcohol) (PVA) as a function of illumination time, excitation intensity, the presence of oxygen, and temperature. We observe nonexponential kinetics related to primary photobleaching through two dark states-the triplet state and a radical anion-and to secondary photobleaching after the optical excitation of those dark states. Reactions of the metastable states with oxygen can lead either to photoproducts or to a recovery of the ground state. Oxygen can therefore enhance or reduce photobleaching, depending on the experimental conditions. At low temperature, photobleaching is reduced although not completely suppressed. Despite the presence of the long-lived radical anion, we are able to observe single R6G molecules in PVA. At room temperature, only relatively bleaching-resistant molecules are resolved as individuals. At low temperature, the observation times become considerably longer. Our study shows that metastable states other than the triplet drastically affect photobleaching.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available