Fluorescence polarization measurements on molecules oriented in liquid crystals

Aligned Immobilization of Proteins Using AC Electric Fields

“…For the determination of the degree of molecular alignment, the modulation depth I mod = ( I ( α ) max − I ( α ) min )/ I ( α ) min of the fluorescence signal was evaluated. The maximal possible modulation of fluorescence intensity in this optical setup was measured with two different polarizing standards: First a reflecting polarizer grid and second the fluorescence dye acridine orange dissolved in the liquid crystal 4‐cyano‐4′‐n‐pentylbiphenyl and being oriented by the guest–host effect in a DC electric field . Both led to the same degree of modulation, which was then normalized to 100%.…”

Development of Laser Dyes to Realize Low Threshold in Dye‐Doped Cholesteric Liquid Crystal Lasers

“…Red and blue lines in Figure 2c and d represent absorption spectra of dye‐doped nematic cells using linearly polarized light parallel and perpendicular to the rubbing direction (director), respectively. It is known that the transition dipole moment of unsubstituted pyrene is parallel to its molecular long axis, whereas that of unsubstituted anthracene is perpendicular to its molecular long axis 24, 25. From these results, it is considered that pyrene and anthracene derivatives are oriented in CLCs as shown in the insets of Figure 2c and d, respectively; that is, the transition dipoles of pyrene and anthracene are perpendicular and parallel to the local director, respectively.…”

Polarized fluorescence and orientational order parameters of a liquid-crystalline conjugated polymer

“…Their elements are linked with orientational order parameters characterizing the orientational distribution function ͑ODF͒. 11 Hence, polarized fluorescence spectroscopy has been extensively used to study orientational characteristics of anisotropic samples such as liquid crystalline materials [12][13][14][15][16][17][18][19] and stretched polymers. [20][21][22][23][24][25][26] We note also that polarized EL is governed by the same matrices and hence the development of polarized backlights and other devices can benefit directly from the information obtained via polarized fluorescence studies.…”