Electrochemical Scanning Tunneling Microscope Imaging of Self-Assembled Monolayer of Double-Stranded DNA on Au(111)

Authors: Guang-Zheng Yang; Lian-Sheng Ling; Li-Jun Wan; Xiao-Hong Fang; Chun-Li Baia

Source: Journal of Nanoscience and Nanotechnology, Volume 4, Number 6, July 2004 , pp. 561-564(4)

Publisher: American Scientific Publishers

Key:

- Free Content

- New Content

- Subscribed Content

- Free Trial Content

Abstract:

Self-assembled monolayer of a double-stranded DNA, which was formed by a 20-nt 5 prime

-thiol-modified oligonucleotide at the interface of Au(111)/solution, has been imaged and studied with electrochemical scanning tunneling microscopy (ECSTM). The results showed that the preferred directions of the adsorbed DNA were <110> and <112>. The measured width of the DNA stripes was 0.95 ± 0.02 nm, which was consistent with the width of dsDNA base pairs. The contour of DNA in the STM image consisted of a series of blobs, which were due to the anchoring of the bases to the substrate along the dsDNA chain. The imaging of a large-scale array of DNA lying flat on the substrate offers a convenient method for the further application of high-resolution STM to the study of the interaction between DNA and a variety of molecules.