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Construction of Helical J‐Aggregates Self‐Assembled from a Thymidylic Acid Appended Anthracene Dye and DNA as a Template
Author(s) -
Iwaura Rika,
OhnishiKameyama Mayumi,
Iizawa Tomohiko
Publication year - 2009
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200802537
Subject(s) - anthracene , crystallography , circular dichroism , fluorescence , aqueous solution , chemistry , self assembly , analytical chemistry (journal) , stereochemistry , materials science , photochemistry , organic chemistry , optics , physics
Driven round the twist by DNA : One‐dimensional helical J‐aggregates are formed by the self‐assembly of thymidylic acid appended anthracene dye (shown in red and yellow) in the presence of complementary single‐stranded oligoadenylic acid (shown in green and blue) in an aqueous solution.The thymidylic acid appended anthracene dye 2,6‐bis[5‐(3′‐thymidylic acid)pentyloxy]anthracene ( 1 ) was synthesized, and the self‐assembly of 1 and the binary self‐assembly of 1 with a complementary single‐stranded 20‐meric oligodeoxyadenylic acid (dA 20 ) were performed in 0.1×TE buffer solution (i.e., 1.0×10 −3 M Tris‐HCl, 1.0×10 −4 M ethylenediaminetriacetic acid (EDTA)). The characteristic J‐band, small Stokes shift (6 nm), Cotton effect, and helical nanofibers 5.1 nm in diameter are observed in UV/Vis, fluorescence, and circular dichroism (CD) spectroscopies and atomic force microscopy (AFM) measurements for the binary self‐assembly of 1 and dA 20 in aqueous solution. These observations revealed that the helical J‐aggregates, in which the short‐axis transition dipoles of the anthracene moieties are aligned in a head‐to‐tail fashion, are formed from the binary self‐assembly of 1 and dA 20 . The UV/Vis absorption and CD band of the anthracene L a region were found to be strongly dependent on temperature and showed cooperative changes for the binary self‐assembly of 1 and dA 20 . The self‐assembly of the single‐component 1 produced right‐ and left‐handed helical nanofibers with diameters ranging from 4.0 to 10 nm. In contrast, for the binary self‐assembly, the UV/Vis and fluorescence spectra showed no J‐band and the Stokes shift was at approximately 107 nm for the single‐component 1 in aqueous solution. In addition, the binary self‐assembly of 1 and noncomplementary single‐stranded 20‐meric oligothymidylic acid (dT 20 ) showed a small J‐band and the J‐band disappeared at 50 °C upon heating. On the basis of these observations, we concluded that thymine–adenine base‐pair formation induced supramolecular helical J‐aggregates in the binary self‐assembly of 1 and dA 20 in aqueous solutions.