Adsorption of Duplex DNA on Mesoporous Silicas: Possibility of Inclusion of DNA into Their Mesopores

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• 作者：Masahiro Fujiwara ; Fumihiro Yamamoto ; Kohta Okamoto ; Kumi Shiokawa ; and Ryoki Nomura
• 刊名：Analytical Chemistry
• 出版年：2005
• 出版时间：December 15, 2005
• 年：2005
• 卷：77
• 期：24
• 页码：8138 - 8145
• 全文大小：321K
• 年卷期：v.77,no.24(December 15, 2005)
• ISSN：1520-6882

文摘

It is well known that a silica surface cannot adsorb duplexDNA in common aqueous solution (not chaotropic solution) because of the electrostatic repulsion of the silicasurface and polyanionic DNA. However, we recently foundthat when duplex DNA in phosphoric acid form (or inacidic solution) was used, DNA was successfully adsorbedinto mesoporous silicas even in low-salt aqueous solution.The adsorption behaviors of DNA into mesoporous silicaswere influenced by the pore diameter sizes. Mesoporoussilicas with 2.80- or 3.82-nm peak pore diameters adsorbed DNA the best in diluted NaCl solution. Formationof the hydrogen bond between P(O)OH groups in DNAand adsorbed water, SiOH groups, or both on silicasurfaces is regarded as a main factor in this adsorption.The coincidence of the pore sizes and DNA diameterrealizes this unique adsorption promoted by the effect ofencompassing DNA with the inner surface of mesoporoussilica. Although there is no clear direct evidence forincluding duplex DNA in the mesopores yet, this adsorption technique is expected to provide a new tool for DNAscience, because DNA in the pore size 2-5 nm indiameter has to be in unusual disentangled thread form.