Generation of circular dichroism from superposed porphyrin films

Abstract

Circular dichroism (CD) was observed from the superposed porphyrin deposited glass plates, which were prepared by the vapor deposition of achiral porphyrin molecules and oriented to one direction by rubbing parallel to the surface of plate. The CD spectra depended on the twisted angle between the plates and the number of plates superposed. The observed CD spectra agreed with the simulated ones by the Mueller matrices superposition calculation using the observed linear dichroism spectra and linear birefringence spectra of each plate.

Generation of Circular Dichroism from Superposed Magnetically Oriented Magnetic Nanoparticles

“…Recently, we have observed CD spectra of porphyrin from the superposed samples of two or three porphyrin layers, which were prepared by vapor deposition of achiral porphyrin molecules on a glass plate and gentle rubbing parallel to the surface of the glass plate to make the molecules linearly oriented to one direction. The observed CD spectra depended on the angle between the rubbing directions of superposed layers and were well interpreted by the superposed Mueller matrix simulations, which used observed linear dichroism (LD) and linear birefringence (LB) …”

“…It is known that the CD signal measured with a conventional CD spectrometer is mainly the m 03 component of the Mueller matrix. ,, Our Mueller matrix analysis of CD spectra of doubly superposed samples has been done by the calculation of the m 03 component of the matrix M (θ 1 , θ 2 ). From the investigation of the contribution of each term to the final m 03 values, it was found that the term of 2LD 0 LB 0 cos 2θ 1 sin 2θ 2 determines 99% of the final value of the CD signal.…”

“…Equation 5 describes approximate Mueller matrices of achiral and low anisotropic samples. 12 Therefore, Mueller matrix calculations of CD spectra of the doubly superposed achiral samples were carried out using the observed LD and LB spectra measured at 0 and 45°for each sample. The component m 00 −m 33 of M(θ 1 , θ 2 ) were represented using LD 1 −LB 1 ′ and LD 2 −LB 2 ′.…”

“…The observed CD spectra depended on the angle between the rubbing directions of superposed layers and were well interpreted by the superposed Mueller matrix simulations, which used observed linear dichroism (LD) and linear birefringence (LB). 12 Circular dichroism has also been observed in the systems, including plasmonic nanoparticles 13−15 and magnetic nanoparticles. 16,17 However, fundamental research to clarify the origin of the optical chirality for achiral nanoparticle systems is less developed.…”

Chiral biosensing at both interband transition and plasmonic extinction regions using twisted-stacked nanowire arrays

“…Moreover, the CD signals achieved their maximum at the twisted angle of 45°, which was in accordance with the previous experimental reports 13,18 and the theoretical simulation results based on the Mueller matrices superposition calculation method. 35 This leads to a readily available method to fabricate TNAs with fine-tuned CD responses in the plasmonic extinction region just by modulating the twisted angles of AgNWs. Such chiral nanostructures, by design, can induce a chiral field at both frequency regions and can be expected to behave distinctively in chiral biosensing.…”