| AVS 54th International Symposium | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS2+BI-ThA |
| Session: | Plasmas in Bioscience |
| Presenter: | N. Vandencasteele, Universite Libre de Bruxelles, Belgium |
| Authors: | B. Broze, Universite Libre de Bruxelles, Belgium N. Vandencasteele, Universite Libre de Bruxelles, Belgium P. Viville, Materia Nova, Belgium R. Lazzaroni, Université Mons Hainaut - Materia Nova, Belgium M. Hecq, Université Mons Hainaut - Materia Nova, Belgium D.G. Castner, University of Washington F. Reniers, Universite Libre de Bruxelles, Belgium |
| Correspondent: | Click to Email |
The adsorption of bovine serum albumine on surfaces is usually a first good test for potential biological applications. In this study, PTFE surfaces were exposed to a remote RF oxygen plasma. The plasma was characterized using optical emission spectrometry, whereas the PTFE surface was characterized using monochromatized XPS, dynamic contact angle and atomic force microscopy. The modified surfaces are then exposed to BSA. The presence of protein was then evidenced by the presence of the N1s peak in the XPS spectrum, by AFM images, and by the change in the contact angle. We show that at low plasma power (or DC-bias) and short treatment times, the contact angle decreases, leading to slightly more hydrophilic surfaces. Small amounts of oxygen (up to 5%) are detected on the surface. BSA adsorbs on these surfaces. An increase in the plasma power leads to an increase of the sample roughness and to an increase of the hydrophobicity. On superhydrophobic (angles above 160°) surfaces, BSA does not absorb any more. No oxygen is present in the XPS spectrum. A correlation was established between the change of the contact angle, the amount of adsorbed protein and the roughness. It is shown that the decrease of the contact angle, and the hysterisis between the advancing and receding angles are good probes for protein adsorption.