Determination of the main forces driving DNA oligonucleotide adsorption onto aminated silica wafers
Determination of the main forces driving DNA oligonucleotide adsorption onto aminated silica wafers
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DOI：
10.1006/jcis.1997.5123
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发表时间：
1997-10-15
影响因子：
9.9
通讯作者：
Mandrand, B
中科院分区：
文献类型：
--
作者：
Balladur, V;Theretz, A;Mandrand, B
研究了20个碱基长的5 ′-氨基连接的寡脱氧核苷酸（ODN）在氨基丙基硅烷修饰的硅胶片上的吸附。首先，硅烷化表面的特征在于接触角测量，X射线光电子能谱（XPS），椭圆偏振仪，和原子力显微镜（AFM）。通过放射性计数或比色杂交反应估计寡核苷酸的吸附量。第一种技术是有用的直接计数，而比色检测，这意味着吸附的ODN和它的互补序列之间的杂交反应，提供有关其在晶片上的可访问性的信息。为了确定ODN吸附到这些表面上的驱动力，已经检查了诸如初始ODN浓度、pH和离子强度的条件。吸附过程符合Langmuir可逆吸附模型。表面电荷的贡献进行了研究，通过提高pH值从4到10.8。带负电荷的ODN和二氧化硅晶片上的胺化基团之间的静电相互作用被发现在吸附过程中发挥了重要作用。离子强度对ODN吸附量有显著影响。(C)北京：科学出版社.
The adsorption of a 20-base long 5'-amino-linked oligodeoxyribonucleotide (ODN) onto aminopropylsilane-modified silica wafers has been investigated. At first, silanized surfaces were characterized by contact angle measurements, X-ray photoelectron spectroscopy (XPS), ellipsometry, and atomic force microscopy (AFM). Adsorbed amount of oligonucleotides was estimated by radioactive counting or colorimetric hybridization reaction. The first technique was useful for direct counting, while colorimetric detection, implying an hybridization reaction between adsorbed ODN and its complementary sequence, provided information about its accessibility on the wafer. With the purpose of determining the driving forces of the ODN adsorption onto these surfaces, conditions such as initial ODN concentration, pH, and ionic strength have been examined. The adsorption process could be described as a Langmuir reversible adsorption type. Surface charge contribution has been investigated by raising pH values from 4 to 10.8. Electrostatic interactions between the negatively charged ODN and the aminated groups on the silica wafers were found to play a major role in the adsorption process. Moreover, a drastic influence of the ionic strength on the ODN adsorbed amount was evidenced. (C) 1997 Academic Press.