Polarization, of fluorescence

M Voigt, M Chambers, and M Grell, On the circular polarization of fluorescence from dyes dissolved in chiral nematic liquid crystals, Chem. Phys. Lett., 347 173-177, 2001. 

Fluorescence polarization is the subject of Chapter 5. Factors affecting the polarization of fluorescence are described and it is shown how the measurement of emission anisotropy can provide information on fluidity and order parameters. 

A report on the change in molecular orientation after grafting is presented by Hayakawa et al. (28), through the angular distribution of polarization of fluorescence on Nylon films grafted with methyl methacrylate, vinyl acetate, and vinyl pyrrolidone, respectively, in liquid phase. 

Morr, C. V., Van Winkle, Q. and Gould, I. A. 1962. Application of polarization of fluorescence technique to protein studies. III. The interaction of x-casein and (3-lacto-globulin. J. Dairy Sci. 45, 823-826. 

Studies of nuclear magnetic resonance spectra (Chapter 3) and of polarization of fluorescence (Chapter 23), have shown that there is rapid though restricted rotational movement of side chains of proteins in solution. Even buried phenylalanine and tyrosine side chains often rotate rapidly whereas movement of the... 

In their study of the polarization of fluorescence of labeled RNase, Young and Potts (264) employed the Scheraga-Mandelkem treatment of the hydrodynamic data and obtained a value of the coefficient J3 = 2.12 X 10 , which is compatible with an axial ratio of 1 2 for an oblate ellipsoid. 

Fig. 2.4. Absorption A, fluorescence F, and degree of polarization of fluorescence P of DMABN and DMABEE (p-dimethylaminobenzoic acid ethylester) in n-hexane at room temperature, c = 5 x 10 M, and ethyl alcohol at 140 K, c = 1 x 10 4Af, respectively. Arrows indicate excitation wavenumber for measurements of P.6 Subscripts A and B refer to final and initial emission, respectively.

Fig. 2.5. The geometry adopted in calculating the degree of polarization V and the anisotropy of polarization of fluorescence 77 at excitation by linear polarized light beam directed along the a -axis with E z.

Let us consider the hyperfine depolarization effect caused by the presence of nuclear spin that is not oriented or aligned by light but acts as a randomly oriented flywheel to reduce the average polarization of fluorescence. The emission process can be effected by the presence of nuclear spin J, even if the hyperfine structure is unresolved by the detection apparatus. For this purpose one has to multiply each polarization moment fq in Eq. (5.34) by a coefficient g(K which is equal to [177, 402]... 

Schessinger, J., Steinberg, I. L., Givol, D., Hochmann, J., and Pecht, I., Antigen-induced conformational changes in antibodies and their Fab fragments studied by circular polarization of fluorescence. Proc. Natl. Acad. Sci. U.S.A. 72, 2775-2779 (1975). 

Most fluorescent substances have rigid structures associated with fused aromatic rings and their fluorescence intensity is practically independent of the viscosity of the environment (4). On the other hand, their rotational movement as a whole will, of course, depend upon the local environment and since such rotations sweep out a larger volume than would be the case for auramine O, for example (i.e., larger V in eq. 2), so that larger domains in the polymeric system can be studied. Any fluorescent system will exhibit a polarization of fluorescence by virtue of the fact that the fluorescent molecules are anisotropic in regard both to emission and to absorption. This anisotropy can be described by fixed axes within the molecule, namely the dichroic axis of the molecule and the emission... 

Fig. . Reciprocal ol degree of polarization of fluorescence versus Tftj for fluorescein conjugate of polyacrylamide in-aqueous glycerol solution and in pure water at various temperatures filled circles, in 9.75% aqueous glycerol solution open circles, in pure water (JO)...

Fig. 8. Reciprocal of degree of polarization of fluorescence versus T/rj for fluorescein conjugates of polyacrylamide in dilute solutions. The weight average molecular weights are 3.5 10 8.4 10 and 23.0 10. for a, b, and c, respectively (redrawn from Fig. 4 of ref. 11)...

The degree of polarization of fluorescence after the absorption of polarized light can tell us whether the excitation has been transferred from one molecule to another. If the same chlorophyll molecules that absorbed polarized light later emit photons when they go back to the ground state, the... 

Rawitch (1972) reported a difference in the rate of rotational diffusion, determined from the polarization of fluorescence, which suggested that the effective molecular volume of a-lactalbumin in solution is larger than for lysozyme, and this difference suggests conformational differences. 

Polarization of Fluorescence in an Electric Field 376 Electric-field-induced Spectra 376... 

Here, we discuss the polarization of fluorescence emission. The spatial orientations of emitting fluorophores determine the polarization of photons emitted. This relationship is the basis of fluorescence depolarization experiments as illustrated in Fig. 4a. When a sample of randomly oriented molecules (e.g., proteins... 

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