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Title
Photophysical Studies of the DNA Microenvironment and Small Molecule-DNA Interactions
Description
Photophysical Studies of the DNA Microenvironment and Small Molecule-DNA Interactions
The photophysical properties of ethidium in a variety of organic solvents, as well as several dsDNAs, were measured. We report that the fluorescence quantum yield of intercalated ethidium is .30(.03), which falls between previous stated measurements of .14 and .60. We believe this to be the most accurately measured fluorescence quantum yield to date, as verified by Strickler-Berg analyses, which exhibit excellent agreement with experimental fluorescence lifetimes. A marked hypochromism upon binding to DNA is noted due to interactions of the dye’s and nucleobases’ respective π-stacks. This more than counteracts the expected increase in transition dipole due to increased conjugation caused by twisting of the phenyl moiety upon intercalation.
The reduced volume cylinder model was tested by the quenching of the fluorescence of an intercalator (ethidium bromide) by a groove binder (methyl viologen). We report that the model is not accurate over a relevant range of DNA concentrations.
The photophysical properties of ethidium in a variety of organic solvents, as well as several dsDNAs, were measured. We report that the fluorescence quantum yield of intercalated ethidium is .30(.03), which falls between previous stated measurements of .14 and .60. We believe this to be the most accurately measured fluorescence quantum yield to date, as verified by Strickler-Berg analyses, which exhibit excellent agreement with experimental fluorescence lifetimes. A marked hypochromism upon binding to DNA is noted due to interactions of the dye’s and nucleobases’ respective π-stacks. This more than counteracts the expected increase in transition dipole due to increased conjugation caused by twisting of the phenyl moiety upon intercalation.
The reduced volume cylinder model was tested by the quenching of the fluorescence of an intercalator (ethidium bromide) by a groove binder (methyl viologen). We report that the model is not accurate over a relevant range of DNA concentrations.
Date Created
2005-05
Contributors
- Engelhart, Aaron (Author)
- Gould, Ian (Thesis director)
- Francisco, Wilson (Committee member)
- Bednar, Valerie (Committee member)
- Barrett, The Honors College (Contributor)
Topical Subject
Resource Type
Extent
27 pages
Language
eng
Copyright Statement
In Copyright
Primary Member of
Series
Academic Year 2004-2005
Handle
https://hdl.handle.net/2286/R.I.30071
Level of coding
minimal
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System Created
- 2017-10-30 02:50:57
System Modified
- 2021-07-16 10:38:41
- 3 years 2 months ago
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