AVS 46th International Symposium
    Biomaterial Interfaces Group Tuesday Sessions
       Session BI-TuM

Paper BI-TuM11
Probing the Oxidation of Amine Modified Surfaces by MALDI Mass Spectrometry

Tuesday, October 26, 1999, 11:40 am, Room 613/614

Session: Protein Solid-Surface Interactions II
Presenter: G.R. Kinsel, University of Texas, Arlington
Authors: G.R. Kinsel, University of Texas, Arlington
R.B. Timmons, University of Texas, Arlington
A.K. Walker, University of Texas, Arlington
Y. Wu, University of Texas, Arlington
Correspondent: Click to Email
The oxidation of amine modified surfaces, produced by pulsed RF plasma polymerization of allyl amine, can lead to substantial changes in the interaction of these surfaces with peptides and proteins in solution. Initial studies, using matrix assisted laser desorption / ionization (MALDI) mass spectrometry to characterize surface-peptide retention affinity, suggest that theses changes result from the acquisition of significant acidic character by the surface during the oxidation process. We have undertaken a variety of studies designed to characterize the surface chemical changes resulting from exposure of amine modified surfaces to air and to quantitate the impact of these changes on the peptide retention affinity. In these studies amine modified surfaces were exposed to pure oxygen and pure carbon dioxide environments. Time dependent changes in surface chemistry were monitored by FTIR spectroscopy and global compositional changes in surface chemistry were monitored by X-ray photoelectron spectroscopy. Subsequently, surface-peptide retention affinities were determined as a function of solution ionic strength and surface oxidation by using MALDI mass spectrometry. In addition, MALDI mass spectrometry was used to directly characterize oxidative changes in low duty cycle allyl amine polymer films to gain insight into the nature of the chemical modifications occurring in these polymer films. The results of these studies provide unique insight into the specific chemical changes and stability / reactivity of these surface modified materials.