Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 253-264 |
| Number of pages | 12 |
| Journal | Ultramicroscopy |
| Volume | 38 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - Dec 1991 |
| Externally published | Yes |
Funding
The authors are grateful to Drs. Brian K. Annis and Gerald J. Bunick for their critical review of this manuscript and to Dr. Arthur Moore of Union Carbide Corporation for his generosity in supplying us with the HOPG substrates. This research was sponsored by the Director's Research and Development Fund at ORNL and the Office of Health and Environmental Research, US Department of Energy under Contract DE-AC05-84OR21400 with Martin Marietta Energy Systems, Inc.
| Funders | Funder number |
|---|---|
| Office of Health and Environmental Research | |
| US Department of Energy | DE-AC05-84OR21400 |
| Oak Ridge National Laboratory |