Effect of hydrophobicity and electrostatics on adsorption and surface diffusion of DNA oligonucleotides at liquid/solid interfaces
Effect of hydrophobicity and electrostatics on adsorption and surface diffusion of DNA oligonucleotides at liquid/solid interfaces
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DOI：
10.1006/jcis.1998.5495
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发表时间：
1998-07-01
影响因子：
9.9
通讯作者：
Graves, DJ
中科院分区：
文献类型：
--
作者：
Chan, V;McKenzie, SE;Graves, DJ
众所周知，静电和疏水相互作用是蛋白质在固/液界面吸附的主要驱动力，但对这些相互作用如何影响单链DNA分子的界面行为知之甚少。这些信息对于DNA杂交传感器的设计是重要的。在这项研究中，全内反射显微镜/荧光恢复后的光漂白（TIR/FRAP）被施加到测量的解吸速率常数和表面扩散系数的21个碱基的寡核苷酸在四个不同的表面，包括两个阳离子氨基硅烷化和两个疏水硅烷化的表面。通过使用相同硅烷化的多孔玻璃珠测定寡核苷酸的吸附等温线。结果表明，寡核苷酸可逆吸附，并与研究的四个表面强烈的相互作用。约50%的寡核苷酸吸附在疏水基板上比阳离子氨基硅烷化的玻璃。脱附速率常数随疏水性硅烷表面层密度的增加而减小，并且取决于基底的化学性质。表面扩散系数取决于在磷酸盐缓冲盐水（pH 7.4）溶液（PBS）中疏水表面上吸附的寡核苷酸的密度。当乙醇被添加到吸附缓冲液中时，疏水二甲基二氯硅烷（DMS）处理的表面以及两个仲氨基硅烷化的玻璃的吸附等温线的初始斜率降低。另一方面，在所有基板上的乙醇的存在下，寡核苷酸的吸附和表面扩散的动力学是独立的基板属性和平衡吸附亲和力。DNA寡核苷酸具有离子和疏水特性，这导致在用一系列离子和疏水硅烷硅烷化的玻璃上的复杂吸附和表面扩散行为。的寡核苷酸躺在表面上的取向和吸附的量似乎是由表面是阳离子还是疏水性的影响。(C)北京：科学出版社.
It is generally known that both electrostatic and hydrophobic interactions are major driving forces for protein adsorption at solid/liquid interfaces, but relatively little is known about how these interactions affect the interfacial behavior of single-stranded DNA molecules. This information is important for the design of DNA hybridization sensors. In this study, total internal reflectance microscopy/fluorescence recovery after photobleaching (TIR/FRAP) was applied to measure the desorption rate constants and the surface diffusion coefficients of a 21-base oligonucleotide on four different surfaces including two cationic amino-silanized and two hydrophobic-silanized surfaces. Adsorption isotherms of the oligonucleotide were determined by using porous glass beads that were identically silanized. The results indicate that the oligonucleotide adsorbs reversibly and interacts strongly with the four surfaces studied. Approximately 50% less oligonucleotide adsorbed on the hydrophobic substrates than on cationic amino-silanized glasses. The desorption rate constant decreases as the density of the hydrophobic silane surface layer increases and it depends on the chemical properties of the substrate. The surface diffusion coefficients depend on the density of the adsorbed oligonucleotides on the hydrophobic surfaces in phosphate-buffered saline (pH 7.4) solution (PBS). When ethanol was added to the adsorption buffer, the initial slopes of the adsorption isotherms for hydrophobic dimethyldichlorosilane-treated (DMS) surface as well as the two secondary amino-silanized glasses were lowered. On the other hand, the kinetics of adsorption and surface diffusion of oligonucleotides in the presence of ethanol on all substrates was independent of the substrate properties and the equilibrium adsorption affinity. DNA oligonucleotides have both ionic and hydrophobic characteristics which result in complex adsorption and surface diffusion behavior on glass silanized with a range of ionic and hydrophobic silanes. The orientation of the oligonucleotide lying on the surface and the quantity adsorbed appear to be influenced by whether the surface is cationic or hydrophobic. (C) 1998 Academic Press.