IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Biomaterials Monday Sessions
       Session BI-MoP

Paper BI-MoP5
Investigation of the Immobilization Process of Peptide Nucleic Acids

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Biorecognition Poster Session
Presenter: J.C. Feldner, Universität Münster, Germany
Authors: J.C. Feldner, Universität Münster, Germany
M. Ostrop, Universität Münster, Germany
O. Friedrichs, Universität Münster, Germany
G. Gappa, Universität Münster, Germany
D. Lipinsky, Universität Münster, Germany
U. Gunst, Universität Münster, Germany
S. Sohn, Universität Münster, Germany
H.F. Arlinghaus, Universität Münster, Germany
Correspondent: Click to Email
In order to immobilize peptide nucleic acid (PNA) onto Au and Ag coated surfaces, a thiol linker (DTSP, 3,3'-Dithio-bis(propionic acid N-hydroxysuccinimide ester)) was used. The immobilization process of DTSP and PNA to these surfaces can be performed by either binding PNA to DTSP in a solution and then immobilizing it onto the surface or immobilizing DTSP onto the surface and then attaching PNA to it. In both methods, PNA binds to the reactive end group of DTSP and the thiol group of DTSP binds to the Au or Ag surface. The reactive end groups of the DTSP layer can be inactivated using primary amines after immobilization of PNA. Deprotenated (M-H)@super-@ signals of the different PNA bases as well as characteristic peaks of DTSP fragments could be used in TOF-SIMS and TP-SIMS (temperature programmed SIMS) measurements to study and optimize the different immobilization processes. A detailed investigation of the concentration of DTSP and its immobilization time on Au and Ag surfaces showed that the best result could be achieved at a concentration of 10 mM and an immobilization time of 24 hr. The binding of PNA to the DTSP layer takes significantly longer than attaching DTSP to the surface. TP-SIMS data, which are very sensitive to bonding strength, showed that characteristic ion signals of the bases start to decrease at a temperature of about 150°C, with differences in the point of onset for the different bases. From the obtained data it can be concluded that the second attachment method described above is preferable to the first one and also has the advantage of allowing to inactivate the complete Au or Ag surface for unspecific DNA attachment.