AVS 52nd International Symposium
    DNA Topical Conference Tuesday Sessions
       Session DN+BI-TuM

Paper DN+BI-TuM9
Measurement of RNA Density of States, Ionization Energy, Work Function and Charge Injection Barriers to Inorganic Materials

Tuesday, November 1, 2005, 11:00 am, Room 311

Session: DNA Surface Characterization
Presenter: J.P. Magulick, University of South Florida
Authors: M.M. Beerbom, University of South Florida
J.P. Magulick, University of South Florida
B. Lagel, University of South Florida
A.J. Cascio, University of South Florida
R. Schlaf, University of South Florida
Correspondent: Click to Email
In light of recent conductivity measurements on single DNA stands, which yielded a wide range of results from insulating to metallic, it is interesting to investigate the electronic structure of oligonucleotides. In our experiments we directly measured the highest occupied molecular orbital (HOMO) density of states, the ionization energy, the work function and the charge injection barriers to graphite and Au of RNA homopolymers. This was achieved using photoemission spectroscopy (PES) in combination with clean multi-step in-vacuum deposition of RNA thin films using a homebuilt electrospray deposition system. This system allows the deposition of macro-molecular materials with a level of control similar to Knudsen cells directly from solution allowing essentially contamination free fabrication of thin films suitable for PES measurements. Furthermore, multi-step depositions without breaking the vacuum are enabled by this technique. Our presentation will give an introduction to the measurement technique, and introduce the experimental set-up. Data from several experiments on RNA homopolymer interfaces to graphite and Au will be discussed, and conclusions with regard to conductivity measurements made.