Pyrene excimer fluorescence

Sahoo D, Narayanaswami V, Kay CM, Ryan RO (2000) Pyrene excimer fluorescence a spatially sensitive probe to monitor lipid-induced helical rearrangement of apolipophorin III. Biochemistry 39 6594-6601... 

Lehrer, S. S. (1997). Intramolecular pyrene excimer fluorescence A probe of proximity and protein conformational change. Fluorescence Spectroscopy 278, 286-295. 

As noted earlier, the limiting lifetime of pyrene excimer fluorescence from concentrated solutions in PS and PMMA glasses was found to be the same as that of pyrene in cyclohexane solution. There have been no similar studies of naphthyl compounds in rigid glasses. Values of k and Q for the [2,6]-naphthalenophanes have not yet been determined for any solvent system. The bis(2-naphthyl) compounds have not been quantitatively characterized in rigid matrices, probably because excimer fluorescence is weak and difficult to detect under such conditions. Given such limited data, it can only be assumed that the values of QD and kD of 2-naphthyl excimers remain the same in rigid solution as in fluid solution. 

As has been previously reported, when pyrene is adsorbed on silica gel there is evidence for ground state association which is not present In solution or the vapor phase.9-13 but which has been described as being present when pyrene is dissolved in a plastic medium. This is also a manifestation of surface inhomogeneity -some sites enhance the tendency to form a ground state bimolecular complex, whereas other sites contain isolated pyrene molecules. The interaction differences are sufficient to yield significant spectral shifts in absorption and the ground state complex emits with the characteristic pyrene excimer fluorescence. Fig. 5 shows a typical set of spectra Illustrating this association and Fig. 6 presents evidence that this observation Is not due to microcrystal formation. 

Pyrene groups were attached to poly(ethylene glycol) (PEG) at both chain ends to allow pyrene excimer fluorescence to be used as a molecular probe of the complexation between PEG and poly(acrylic acid) (PAA). The excimer to monomer intensity ratio, was... 

Pyrene excimer fluorescence was used as a sensitive proximity probe in the intermolecular complex system. Upon addition of PAA solution, the intramolecular mobility of the PEG chain was suppressed resulting in decreased intramolecular excimer formation. Simultaneously, the local concentration of PEG is increased in the vicinity of PAA. The excimer formation seems to result from the arrangement of pyrene groups which is already pre-formed in the ground state. The effect of complexation is observed to be more pronounced in the PEG-PAA with a higher molecular weight of PAA. A more complete account of this work will appear elsewhere. (16,17)... 

Fig. 14. Growing-in profiles of pyrene excimer fluorescence on various silica surfaces. Laser pulse is also presented. (Reprinted with permission from Langmuir, 2 (1986) 616, our ref. (40), Copyright (1986) American Chemical Society).

A. K. Soutar, H. J. Pownall, A. S. Hu, and L. C. Smith, Phase Transitions in Bilamellar Vesicles. Measurements by Pyrene Excimer Fluorescence and Effect on Transacylation by Lecithin Cholesterol Acyltransferase, Biochemistry 13, 2828-2836 (1974). 

Duhamel J (2012) New insights in the study of pyrene excimer fluorescence to characterize macromolecules and their supramolecular assemblies in solution. Langmuir 28 (16) 6527-6538. doi 10.1021Aa2047646... 

Associative Behavior of Pyrene Singly (Pyj-PEO) and Doubly (Py2-PEO) End-Labeled PEOs Due to their similarity to HEURs, namely a stretch of linear PEO terminated at both ends with a hydrophobe, the hydrophobic associations induced by pyrene doubly labeled PEOs have been under scientific scrutiny for more than three decades. In 1982, Winnik reported that an aqueous solution of a 9.6K PEO chain end capped with 1-pyrenebutyric acid yielded an unexpectedly high 7e//m ratio compared to the value obtained in 10 organic solvents [64]. This result represented a solid evidence that hydrophobic associations were taking place in water between the hydrophobic pyrene labels of Py2-PEO(9.6K). The demonstration that pyrene excimer fluorescence reflected the level of hydrophobic associations between the pyrene labels of Py2-PEO led to further and more detailed investigations. 

Betcher-Lange, S.L., Lehrer, S.S. Pyrene excimer fluorescence in rabbit skeletal alphaalpha-tropomyosin labeled with N-(l-pyrene)maleimide. A probe of sulfhydryl proximity and local chain separation. J. Biol. Chem. 253, 3757-3760 (1978)... 

Marks, H. S. Anderson, C. R. Determination of putrescine and cadaverine in seafood (tin fish and shellfish) by liquid chromatography using pyrene excimer fluorescence. J. Chromatogr., A 2005,1094, 60-69. 

Santra, M. K. Dasgupta, D. Panda, D. Pyrene excimer fluorescence of yeast alcohol dehydrogenase a sensitive probe to investigate ligand binding and unfolding pathway of the enzyme. Photochem. Photobiol. 2006,82,480-486. 

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