AVS 50th International Symposium
    Applied Surface Science Tuesday Sessions
       Session AS+BI-TuA

Paper AS+BI-TuA9
Photoionization for Trace Measurement of DNA on Surfaces

Tuesday, November 4, 2003, 4:40 pm, Room 324/325

Session: Biomaterials Characterization
Presenter: J.F. Moore, Argonne National Laboratory
Authors: J.F. Moore, Argonne National Laboratory
W.F. Calaway, Argonne National Laboratory
B.V. King, University of Newcastle, Australia
J.W. Lewellen, Argonne National Laboratory
S.V. Milton, Argonne National Laboratory
M.J. Pellin, Argonne National Laboratory
M. Petravic, Australian National University
I.V. Veryovkin, Argonne National Laboratory
G.L. Woloschak, Northwestern University
Correspondent: Click to Email
Recent developments in vacuum ultraviolet (VUV) lasers allow new photoionization techniques to be applied to surface and interface analysis problems. Single photon ionization of laser desorbed nucleosides and DNA was performed using a molecular F@SUB 2@ laser (wavelength 157 nm, pulse energy 8 mJ, pulse length 10 ns) and a tunable free electron laser (wavelength 120 - 265 nm, pulse energy 0.1 mJ, pulse length 300 fs). Results including detection limit and degree of fragmentation are compared for several systems including guanosine and single-stranded DNA of 10-30 base pair lengths. The tunability of the free electron laser to a wavelength just above the ionization potential of the analyte molecule can be used to enhance selectivity and sensitivity of the analysis. There are clear applications of this sensitive, selective, spatially resolving technique that is capable of identifying mutated or adducted DNA with little sample preparation. These uses will be elaborated on in the context of our results and plans for further technique development, and operational experience with the free electron laser. @FootnoteText@ This work is supported by the U. S. Department of Energy, BES-Materials Sciences, under Contract W-31-109-ENG-38.