Fluorescence anisotropy measurements in solution: Methods and reference materials (IUPAC Technical Report)

Abstract

After recalling the basic relations relevant to both steady-state and time-resolved fluorescence polarization, it is shown how the values of steady-state polarized intensities recorded experimentally usually need to be corrected for systematic effects and errors, caused by instrumentation and sample properties. A list of selected reference values of steady-state fluorescence anisotropy and polarization is given. Attention is also paid to analysis of time-resolved fluorescence anisotropy data obtained by pulse fluorometry or phase and modulation fluorometry techniques. Recommendations for checking the accuracy of measure ments are provided together with a list of selected time-resolved fluorescence anisotropy data as reported in the literature.

Ultrafast Electronic Energy Transfer Beyond the Weak Coupling Limit in a Proximal but Orthogonal Molecular Dyad

“…For a rod-like emitter, a value of r = 0.4 ± 0.03 indicates a dipole lying parallel to the excitation polarization, while a value of r = -0.2 ± 0.01 is obtained if the emission dipole lies perpendicular to excitation. 27 Emission is normally recorded at an angle of 54.7° to the excitation polarization, the so-called "magic angle" which nullifies polarization effects, and indeed was used for the data presented in Figure 2. To record emission parallel and perpendicular to excitation, we used a Berek compensator to rotate the polarization of the excitation beam with respect to the detector.…”

“…Anisotropy can be a powerful descriptor of orientations in the molecular dyad and additional information can be extracted beyond the time constant for depolarization. The final anisotropy value, rinf, is -0.06 ± 0.005, and can be related 27 to an angle of orientation with respect to excitation through Equation 2, where  is the angle and r is the anisotropy. Directly calculated for r = -0.06 ± 0.005 this gives an  value of 61°, however due consideration has to be given to the small amount (i.e., ca.…”

Characterization of photoluminescence measuring systems (IUPAC Technical Report)

“…[39]; iii. additional optical components such as filters or attenuators used in the excitation and emission channel; iv.…”

Calibration, standardization, and quantitative analysis of multidimensional fluorescence (MDF) measurements on complex mixtures (IUPAC Technical Report)

“…Polarization: Polarization (or anisotropy) phenomena in some samples must also be factored into any calibration procedure [36], as there can be a significant effect on measured intensity. This is particularly Unauthenticated Download Date | 5/13/18 9:04 AM important when the sample includes slow moving macromolecules like proteins [37], polymers, viscous petroleum fluids, or asphaltenes [38].…”