Optical properties of an immobilized DNA monolayer from 255 to 700 nm
Optical properties of an immobilized DNA monolayer from 255 to 700 nm
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DOI：
10.1021/la049653
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发表时间：
2004-06-22
期刊：
影响因子：
3.9
通讯作者：
Saraf, RF
中科院分区：
文献类型：
--
作者：
Elhadj, S;Singh, G;Saraf, RF
在255-700 nm范围内测量27个核苷酸（nt）单链DNA（ssDNA）和相应的双链DNA（dsDNA）的固定单层的真实的（n）和虚部（k）折射率。使用多种技术来获得一致的估计。覆盖率约为6.5%，平均链间距约为11.8 nm，明显大于单链在表面的“足迹”。在ssDNA和dsDNA之间测量到的n的增加接近5%，比由于分子量加倍而引起的预期变化小20%。k的变化不显著，表明在dsDNA中预期的由于碱基对堆积的电子离域效应在光学频率下不重要。
The real (n) and imaginary (k) refractive indices of an immobilized monolayer of 27 nucleotide (nt) single stranded DNA (ssDNA) and the corresponding double stranded DNA (dsDNA) are measured in the 255-700 nm range. Multiple techniques are used to obtain consistent estimation. The coverage is similar to6.5% with an average interchain distance of tethered ssDNA molecules of similar to11.8 nm, which is significantly larger than the "footprint" of the chain on the surface. The measured increase in n by similar to5% between the ssDNA and the dsDNA is 20% smaller than the expected change due to doubling of the molecular weight. The change in k is not significant, indicating that the electron delocalization effect expected in dsDNA due to base pair stacking is not important at optical frequencies.