Fluorescence Detected Circular Dichroism for Highly Sensitive Observation of Exciton Coupled CD

AbstractMeasurements of the electronic circular dichroism (CD) are highly sensitive to the absolute configuration and conformation of chiral molecules and supramolecular assemblies and have therefore found widespread application in the chemical and biological sciences. Here, we demonstrate an approach to simultaneously follow changes in the CD and absorption response of photoexcited systems over the ultraviolet−visible spectral range with 100 fs time resolution. We apply the concept to chiral polyfluorene copolymer thin films and track their electronic relaxation in detail. The transient CD signal stems from the supramolecular response of the system and provides information regarding the recovery of the electronic ground state. This allows for a quantification of singlet−singlet annihilation and charge-pair formation processes. Spatial mapping of chiral domains on femtosecond time scales with a resolution of 50 μm and diffraction-limited steady-state imaging of the circular dichroism and the circularly polarised luminescence (CPL) of the films is demonstrated.

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A Design of Cesium Atomic Magnetometer Based on Circular Dichroism

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.203.268 ◽

2012 ◽

Vol 203 ◽

pp. 268-272 ◽

Cited By ~ 1

Author(s):

Xian Jin Zeng ◽

Mo Si Hao ◽

Qing Meng Li ◽

Qiang Liu ◽

Jun Hai Zhang ◽

...

Keyword(s):

Magnetic Field ◽

Circular Dichroism ◽

Spin Exchange ◽

Laser Light ◽

Tracking System ◽

Frequency Tracking ◽

Highly Sensitive ◽

Optical Configuration ◽

Circular Dichroïsm ◽

The Magnetic Field

Recently, atomic magnetometers have been reported as the most sensitive magnetometers by completely eliminating the spin exchange relaxation. In this paper, we described a design of highly sensitive cesium atomic magnetometer based on circular dichroism, which had the advantage of easily locking the probing laser to the necessary frequency compared with those based on circular birefringence. In order to polarize the cesium atoms uniformly, the pumping laser light was separated into two counter-propagating and counter-circular polarization beams through the atomic vapor cell. We employed a circular analyzer optical configuration to measure the ellipticity of the probing light, which indicated the amplitude of the magnetic field. The external magnetic field was tracked by a digital auto frequency tracking system.

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Characterization of Tamm-Horsfall Urinary Glycoprotein

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007254x ◽

1973 ◽

Vol 31 ◽

pp. 420-421

Author(s):

John P. Robinson ◽

J. David Puett

Keyword(s):

Electron Microscopy ◽

Circular Dichroism ◽

Secondary Structure ◽

Quaternary Structure ◽

Normal Adult ◽

Morphological Properties ◽

Adult Males ◽

Circular Dichroïsm ◽

Urinary Glycoprotein

Much work has been reported on the chemical, physical and morphological properties of urinary Tamm-Horsfall glycoprotein (THG). Although it was once reported that cystic fibrotic (CF) individuals had a defective THG, more recent data indicate that THG and CF-THG are similar if not identical.No studies on the conformational aspects have been reported on this glycoprotein using circular dichroism (CD). We examined the secondary structure of THG and derivatives under various conditions and have correlated these results with quaternary structure using electron microscopy.THG was prepared from normal adult males and CF-THG from a 16-year old CF female by the method of Tamm and Horsfall. CF female by the method of Tamm and Horsfall.

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