东南大学学报（英文版）2016，Vol.32Issue(1)：45-50,6.DOI:10.3969/j.issn.1003-7985.2016.01.009
利用表面力仪研究单链 DNA在云母表面的吸附与解吸附特性
Adsorption and desorption behaviors of ssDNA molecules on mica surface by surface forces apparatus
蔡迪 1阚亚鲸 1赵古田 1伍根生 1司伟 1谭启檐 1陈云飞1
作者信息
摘要
Abstract
An approach for studying the adsorption and desorption behaviors of single-stranded DNA ssDNA molecules on the mica surface by the surface forces apparatus SFA is reported which can be used to characterize the precise thickness configuration and mechanical properties of ssDNA layers on the mica surface at a certain buffer solution. The formation of ssDNA layers is first studied by tuning the ssDNA concentrations and the experimental results indicate that the ssDNA concentration of 100 ng/μL is ideal for forming a ssDNA monolayer structure on the mica surface and the hardwall value measured to be 1.04 nm under this circumstance is regarded as the thickness of the ssDNA monolayer confined on mica. The desorption behavior of ssDNA molecules from the mica surface is further studied by observing and comparing different shapes of the force-distance curves under certain conditions.It is found that the desorption of ssDNA molecules from the mica surface occurs as the monovalent salts are added into the gap buffer.It is inferred that the competition effect between monovalent and divalent salts can induce the release of ssDNA from substrate.The results also reveal that 10 mmol/L monovalent salts Na+ is sufficient for the desorption of ssDNA from mica.This work provides an applicable method to study the binding mechanism of ssDNA molecules on inorganic substrates.关键词
单链DNA/云母/吸附/解吸附/竞争效应/表面力仪Key words
single-stranded/DNA/mica/adsorption desorption/competition effect/surface forces apparatus分类
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蔡迪,阚亚鲸,赵古田,伍根生,司伟,谭启檐,陈云飞..利用表面力仪研究单链 DNA在云母表面的吸附与解吸附特性[J].东南大学学报（英文版）,2016,32(1):45-50,6.
