Temperature Dependence of the STM Morphology and Electronic Level Structure of Silver-Containing DNA.

Understanding the effect of external conditions, temperature in particular, on novel nanomaterials is of great significance. The powerful ability of scanning tunneling microscopy (STM) to characterize topography and electronic levels on a single molecule scale is utilized herein to characterize individual silver-containing poly(dG)-poly(dC) DNA molecules, at different temperatures. These measurements indicate that the molecule is a truly hybrid metal-organic nanomaterial with electronic states originating from both the DNA and the embedded silver. The temperature dependence of this density of states (DOS) leads to the temperature dependent STM apparent height of the molecule-a phenomenon that has not been observed before for other complex nanostructures.