Brown G M, Allison D P, Warmack R J, Jacobson K B, Larimer F W, Woychik R P, Carrier W L
Chemistry Division, Oak Ridge National Laboratory, TN 37831.
Ultramicroscopy. 1991 Dec;38(3-4):253-64. doi: 10.1016/0304-3991(91)90160-8.
In a scanning tunneling microscope (STM) electrochemical cell we have studied the effects of electrode potential on both the surface topography and the adsorption of deoxyribonucleic acid (DNA) to graphite and gold surfaces. Images of the surface of highly oriented pyrolytic graphite (HOPG), of the same area, in response to a positive increase in surface potential show degradation of the step edges with little change in the crystal plane. Images of the same area of a gold surface demonstrate the formation of and the progressive increase in nodular structures on the crystal planes, in response to increased potential, with little effect on the step edges. Using radio-labeled DNA we monitored electrochemical absorption onto HOPG and gold surfaces. Although at no applied potential and at negative surface potentials some DNA was bound, at positive potentials 3 to 5 times more DNA was incorporated onto both surfaces. DNA adsorbed to a surface at a positive potential was not removed by reversing the potential.
在扫描隧道显微镜（STM）电化学池中，我们研究了电极电位对表面形貌以及脱氧核糖核酸（DNA）在石墨和金表面吸附的影响。相同面积的高度定向热解石墨（HOPG）表面图像显示，随着表面电位正向增加，台阶边缘出现降解，而晶面变化不大。金表面相同区域的图像表明，随着电位增加，晶面上会形成结节状结构并逐渐增多，而对台阶边缘影响较小。我们使用放射性标记的DNA监测其在HOPG和金表面的电化学吸附。尽管在未施加电位和负表面电位时会有一些DNA结合，但在正电位下，两个表面上结合的DNA量要多3至5倍。在正电位下吸附到表面的DNA不会因电位反转而被去除。
