Abstract/Details

Lifetime resolved fluorescence correlation spectroscopy and two-photon spectroscopy of amyloid nanotube bundles


2009 2009

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Abstract (summary)

Fluorescence correlation spectroscopy (FCS) has been widely used to investigate molecular dynamics and interactions in biological systems. However, these diffusion based assays currently have a major limitation, which requires that the diffusion coefficients of component species in a sample must be substantially different in order to be resolved. This limitation can be overcome, and the resolution of FCS measurements can be enhanced, by combining FCS measurements with measurements of fluorescence lifetimes. We show that we can dramatically enhance resolution in FCS measurements using global analysis on simultaneously acquired FCS and lifetime data. The method accurately resolves the concentration and diffusion coefficients of multiple sample components, even when their diffusion coefficients are identical, provided that there is a difference in the lifetime of the component species. We show examples of this technique by using both simulations and experiments. It is expected that this method will be of significance for a broad range of researchers studying molecular interactions. In a separate project, a potentially useful amyloid nanotube bundle material from the β-amyloid proteins is studied. We used two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) to investigate the photophysical properties of this material. The emission properties of the bundles are characterized, and their dependence on the moisture level is revealed. The mechanism of the intrinsic fluorescence is discussed to be related to the electron delocalization within the peptides. The spectroscopic and microscopic study of the amyloid nanotube bundles may open up interesting new perspectives in the bio-inspired material science area.

Indexing (details)


Subject
Molecular physics;
Optics;
Biophysics
Classification
0609: Molecular physics
0752: Optics
0786: Biophysics
Identifier / keyword
Pure sciences; Biological sciences; Amyloid; Fluorescence correlation spectroscopy; Nanotube bundles
Title
Lifetime resolved fluorescence correlation spectroscopy and two-photon spectroscopy of amyloid nanotube bundles
Author
Guo, Peng
Number of pages
97
Publication year
2009
Degree date
2009
School code
0665
Source
DAI-B 71/03, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
9781109651621
Advisor
Berland, Keith
Committee member
Dunlap, David; Finzi, Laura; Rasnik, Ivan; Warncke, Kurt; Weeks, Eric
University/institution
Emory University
Department
Physics
University location
United States -- Georgia
Degree
Ph.D.
Source type
Dissertations & Theses
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
3396612
ProQuest document ID
305086710
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
http://search.proquest.com/docview/305086710
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