Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
J Phys Chem B. 2013 Feb 28;117(8):2267-72. doi: 10.1021/jp3096715. Epub 2013 Feb 14.
We demonstrate a new procedure for separation of single-stranded DNA (ssDNA) fragments that are anchored to the surface of a gold electrode by end hybridization. The new separation procedure takes advantage of the strong yet evolving nonuniform electric field near the gold surface in contact with a buffer solution gradually being diluted with deionized water. Separation of short ssDNA fragments is demonstrated by monitoring the DNA at the gold surface with in situ fluorescence measurement. The experimental results can be rationalized with a simple theoretical model of electric double layer that relates the strength of the surface pulling force to the ionic concentration of the changing buffer solution.
我们展示了一种新的分离方法，用于分离通过末端杂交固定在金电极表面的单链 DNA（ssDNA）片段。新的分离方法利用了与缓冲溶液接触的金表面附近的强但不断变化的非均匀电场，该电场逐渐被去离子水稀释。通过原位荧光测量监测金表面的 DNA，证明了短 ssDNA 片段的分离。实验结果可以用简单的双电层理论模型来合理化，该模型将表面拉力的强度与变化的缓冲溶液的离子浓度联系起来。
