Adsorption of synthetic homo- and hetero-oligodeoxynucleotides onto highly oriented pyrolytic graphite: Atomic force microscopy characterization
Adsorption of synthetic homo- and hetero-oligodeoxynucleotides onto highly oriented pyrolytic graphite: Atomic force microscopy characterization
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DOI：
10.1016/j.bpc.2005.12.017
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发表时间：
2006-05-20
影响因子：
3.8
通讯作者：
Oliveira Brett, Ana Maria
中科院分区：
文献类型：
--
作者：
Chiorcea Paquim, Ana-Maria;Oretskaya, Tatiana S.;Oliveira Brett, Ana Maria
DNA在电极表面的吸附是基于DNA的生物传感器发展的基础。利用磁性交流模式原子力显微镜（MAC mode AFM）研究了10聚人工合成寡脱氧核苷酸（ODNs）在高取向热解石墨（HOPG）表面的自由吸附。核酸与碳电极表面相互作用的机制被阐明，使用已知碱基序列的10-mer合成同源和异odn序列，因为它们可以清楚地解释实验数据。空气中的AFM图像显示了不同的ODN的吸附模式和HOPG表面覆盖程度，以及与每个ODN分子的单个结构和碱基序列的相关性。结果表明，与HOPG疏水表面的疏水相互作用解释了主要的吸附机制，尽管静电和范德华相互作用等其他作用可能有助于自由吸附过程。根据ODN序列的疏水特性，ODN与H OPG表面的相互作用不同，直接取决于分子质量、单个碱基的疏水特性和分子的二级结构。研究了ODN链末端存在的碱基类型对吸附过程的重要性，同一组碱基以不同顺序排列组成的ODN序列获得了不同的吸附模式。(c) 2006 Elsevier B.V.版权所有
DNA adsorption on electrode surfaces is of fundamental interest for the development of DNA-based biosensors. The free adsorption of 10-mer synthetic oligodeoxynucleotides (ODNs) onto highly oriented pyrolytic graphite (HOPG) surfaces was studied using Magnetic AC mode atomic force microscopy (MAC Mode AFM). The mechanism of interaction of nucleic acids with carbon electrode surfaces was elucidated, using 10-mer synthetic homo- and hetero-ODNs sequences of known base sequences, because they allow clear interpretation of the experimental data. AFM images in air revealed different adsorption patterns and degree of HOPG surface coverage for the ODNs, and correlation with the individual structure and base sequence of each ODN molecule will be presented. The results demonstrated that the hydrophobic interactions with the HOPG hydrophobic surface explain the main adsorption mechanism, although other effects such as electrostatic and Van der Waals interactions may contribute to the free adsorption process. The ODNs interacted differently with the H OPG surface, according to the ODN sequence hydrophobic characteristics, being directly depending on the molecular mass, the hydrophobic character of the individual bases and on the secondary structure of the molecule. The importance of the type of base existent at the ODN chain extremities on the adsorption process was investigated and different adsorption patterns were obtained with ODN sequences composed by the same group of bases aligned in a different order. (c) 2006 Elsevier B.V. All rights reserved.