AVS 50th International Symposium
    Applied Surface Science Friday Sessions
       Session AS-FrM

Paper AS-FrM3
Characterisation of Peptides Using TOF-SIMS with Polyatomic Primary Ion Bombardment

Friday, November 7, 2003, 9:00 am, Room 324/325

Session: SIMS
Presenter: B. Hagenhoff, TASCON GmbH, Germany
Authors: K. Pfitzer, TASCON GmbH, Germany
E. Tallarek, TASCON GmbH, Germany
R. Kersting, TASCON GmbH, Germany
B. Hagenhoff, TASCON GmbH, Germany
Correspondent: Click to Email
In the 80s of the last century it could be shown that the optimum sample preparation for SIMS of peptides under monoatomic primary ion bombardment is a monolayer preparation on noble metal substrates.@footnote 1,2@ Yields from thick overlayers turned out to be distinctly lower compared to the monolayer preparation. Although many applications were possible by this type of preparation, information could not be gained from biological material directly where peptides or proteins are embedded in thick organic matrices. Now, the use of polyatomic primary ions offers new opportunities. Under such primary ion bombardment conditions molecular ions can be emitted with high secondary ion formation efficiency also from thick organic layers. Efficiency enhancement factors can reach up to 3 orders of magnitude.@footnote 3@ We have applied Ga@super +@, Au@sub 1@@super +@, Au@sub 2@@super +@, Au@sub 3@@super +@ as well as Au@sub 5@@super +@ bombardment to several peptides. The peptide masses varied from 1000u up to 3500u. Variations of the chemical structure could be tested by varying the number of basic and acidic side chains. The samples were prepared as monolayers on noble metal substrates, as thick overlayers (powders, thick layers spin coated from solutions) as well as mixed into nitrocellulose. The results show that polyatomic primary ion bombardment indeed allows to desorb peptides efficienctly from thick layers. Progress can therefore be expected for SIMS imaging of peptides and proteins in biological matter. @FootnoteText@ References: @footnote 1@ A. Benninghoven; J. Vac. Sci. Technol. A3 (3), (1985), 451 @footnote 2@ D. van Leyen, D. Greifendorf, A. Benninghoven in: A. Benninghoven, A. M. Huber, H. W. Werner (eds.); Secondary Ion Mass Spectrometry (SIMS VI); John Wiley & Sons, Chichester, 1988, 679 @footnote 3@ D. Stapel, M. Thiemann, B. Hagenhoff, A. Benninghoven, in: A. Benninghoven, P. Bertrand, H. N. Migeon, H. W. Werner (eds.); Secondary Ion Mass Spectrometry (SIMS XII); John Wiley & Sons, Chichester, 2000, 255