title: Imaging of transverse electron transfer through a DNA molecule by simultaneous scanning tunneling and frequency-modulation atomic force microscopy.
abstract: Simultaneous scanning tunneling and frequency-modulation atomic force microscopy (STM/FM-AFM) was applied to a DNA molecule on a Cu(111) surface to analyze transverse electron transfer which is related to the electron transfer and the electrical contact in DNA-based devices. In particular, we demonstrated correlation mapping of the electron transfer parameters by visualizing specific combinations of the decay constant β and the contact conductance G. The results clearly revealed that electron transfer across the DNA strand varies spatially in the DNA molecule. This spatial variation is probably correlated with deformation of DNA on the surface. From quantitative analysis, the decay constant β was estimated to be 3.3 nm(-1), which is consistent with previously reported values for π-conjugated molecules.
authors.affiliation: Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology, 1-8-31, Midorigaoka, Ikeda, Osaka 563-8577, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Maeda
authors.forename: Takuya
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Tomoji
authors.initials: T
authors.lastname: Kawai