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Oriented structure of octadecyl acridine orange intercalated in the monolayer and Langmuir–Blodgett film of octadecyl adenine‐thymine base pairs
Author(s) -
Fujita Kyoko,
Nakamura Fumio,
Ohno Hiroyuki
Publication year - 2004
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.511
Subject(s) - langmuir–blodgett film , acridine orange , thymine , acridine , monolayer , materials science , base (topology) , orange (colour) , photochemistry , dna , crystallography , stereochemistry , organic chemistry , chemistry , nanotechnology , biochemistry , apoptosis , mathematical analysis , mathematics , food science
The oriented structure of acridine orange (AO) in both monolayer and Langmuir–Blodgett (LB) film has been studied by optical waveguide (OWG) spectroscopy using polarized incident light. Mixed monolayer and LB films, consisting of octadecyl acridine orange (C 18 ‐AO) incorporated in stacked base pairs of octadecyl adenine (C 18 ‐Ade) and octadecyl thymine (C 18 ‐Thy), were prepared on a quartz waveguide. Absorption of transverse electric field (TE) polarized light was about twice that of transverse magnetic field (TM) polarized light. Both OWG spectra have λ max at 500 nm, which is characteristic of monomeric AO molecules. This result strongly suggests that C 18 ‐AO molecules were dispersed uniformly in the mixed monolayer and were excited more effectively by the TE polarized light. Since the absorption moment of AO molecules is related to their long axis, it is proposed that C 18 ‐AO molecules are incorporated in C 18 ‐Ade/C 18 ‐Thy pairs with the long axis parallel to the layer surface. The absorbance at 500 nm was proportional to the number of layers on the waveguide. The dichroic ratio of the absorbance at 500 nm for TE polarized light to that for TM polarized light was constant regardless of the number of layers. The C 18 ‐AO molecules were uniformly incorporated in each layer with the long axis relatively parallel to the layer surface. Copyright © 2004 John Wiley & Sons, Ltd.