Nanostructured Self-Assembly of Double-Stranded DNA/Poly(o-methoxyaniline) Hybrid

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• 作者：Arnab Dawn ; Arun K. Nandi
• 刊名：Journal of Physical Chemistry C
• 出版年：2007
• 出版时间：May 3, 2007
• 年：2007
• 卷：111
• 期：17
• 页码：6268 - 6274
• 全文大小：489K
• 年卷期：v.111,no.17(May 3, 2007)
• ISSN：1932-7455

文摘

Biomolecular hybrids of poly(o-methoxyaniline) (POMA) and deoxyribonucleic acid (DNA) are prepared byreacting protonated and sodium salt forms of DNA with emeraldine base (EB) and emeraldine salt (ES)forms of POMA, respectively. Wide-angle X-ray scattering (WAXS) studies indicate that the DNA double-helical structure remains unaltered in the hybrid. Fourier transform infrared (FTIR) and UV-vis studies indicatethat there is specific interaction between the radical cation of POMA produced due to doping and the DNAanion. Transmission electron micrographs (TEM) of the Na-DNA/POMA-ES system show a fibrillar networkstructure of invariant fibrillar diameter for different hybrid compositions. In contrast, the protonated-DNA/POMA-EB system exhibits a fibrillar network structure where fibrillar diameter does vary with hybridcomposition. The doping level and concentration of POMA-EB are attributed for the difference in fibrillardiameter with composition in protonated-DNA/POMA-EB hybrids. In the Na-DNA/POMA-ES system, thecross section of each DNA strand immobilizes approximately 30 POMA chains irrespective of the compositionof the hybrid, and this has been attributed to the constant doping level ([Cl]/[N] = 0.52) of POMA-ES. Thecombination of 19 such units approximately produces the fibril of the Na-DNA/POMA-ES system. Thus theTEM micrographs present firm evidence of wrapping of double-stranded DNA by POMA chains. Anapproximate model of the Na-DNA/POMA-ES system (doping level of 0.52) indicates nanostructured self-organized assembly of the components in the hybrid.