Nabok Alexei, Tsargorodskaya Anna, Davis Frank, Higson Séamus P J
Sheffield Hallam University, Materials and Engineering Research Institute, Sheffield S1 1WB, UK.
Biosens Bioelectron. 2007 Oct 31;23(3):377-83. doi: 10.1016/j.bios.2007.04.020. Epub 2007 May 6.
The adsorption of genomic DNA and subsequent interactions between adsorbed and solvated DNA was studied using a novel sensitive optical method of total internal reflection ellipsometry (TIRE), which combines spectroscopic ellipsometry with surface plasmon resonance (SPR). Single strands of DNA of two species of fish (herring and salmon) were electrostatically adsorbed on top of polyethylenimine films deposited upon gold coated glass slides. The ellipsometric spectra were recorded and data fitting utilized to extract optical parameters (thickness and refractive index) of adsorbed DNA layers. The further adsorption of single stranded DNA from an identical source, i.e. herring ss-DNA on herring ss-DNA or salmon ss-DNA on salmon ss-DNA, on the surface was observed to give rise to substantial film thickness increases at the surface of about 20-21 nm. Conversely adsorption of DNA from alternate species, i.e. salmon ss-DNA on herring ss-DNA or herring ss-DNA on salmon ss-DNA, yielded much smaller changes in thickness of 3-5 nm. AFM studies of the surface roughness of adsorbed layers were in line with the TIRE data.
使用一种新型灵敏的全内反射椭圆偏振光谱法（TIRE）研究了基因组DNA的吸附以及吸附态和溶剂化DNA之间的相互作用，该方法将光谱椭圆偏振法与表面等离子体共振（SPR）相结合。两种鱼类（鲱鱼和鲑鱼）的单链DNA静电吸附在沉积于镀金载玻片上的聚乙烯亚胺薄膜表面。记录椭圆偏振光谱并利用数据拟合来提取吸附DNA层的光学参数（厚度和折射率）。观察到来自相同来源的单链DNA，即鲱鱼单链DNA吸附在鲱鱼单链DNA上或鲑鱼单链DNA吸附在鲑鱼单链DNA上，在表面会导致膜厚度显著增加约20 - 21 nm。相反，来自不同物种的DNA吸附，即鲑鱼单链DNA吸附在鲱鱼单链DNA上或鲱鱼单链DNA吸附在鲑鱼单链DNA上，产生的厚度变化要小得多，为3 - 5 nm。吸附层表面粗糙度的原子力显微镜研究结果与全内反射椭圆偏振光谱法数据一致。
