AVS 52nd International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP23
Adsorption of Human Serum Albumin on Carbon Nitride Films Studied with in-situ Ellipsometry

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Biomaterial Interfaces Poster Session
Presenter: T. Berlind, Linköping University, Sweden
Authors: T. Berlind, Linköping University, Sweden
M. Poksinski, Linköping University, Sweden
L. Hultman, Linköping University, Sweden
P. Tengvall, Linköping University, Sweden
H. Arwin, Linköping University, Sweden
Correspondent: Click to Email
Carbon based materials have received considerable attention during the last decades due to their interesting tribological, electronic and optical properties. So far not much effort has been put into the investigation of the use of these materials in biotechnology. The objective with this study is to investigate the interaction of carbon and carbon nitride surfaces with proteins. Carbon nitride (CN@sub x@) and amorphous carbon (a-C) thin films were deposited on silicon substrates by reactive sputtering. By changing sputtering parameters the microstructure can be controlled and amorphous, graphitic and fullerene-like films were grown to a thickness of 200 nm. Prior to protein adsorption, the three structures of CN@sub x@ films and the a-C films were optically characterized with spectroscopic ellipsometry in the wavelength range 350-1700 nm and with infrared ellipsometry in the range 2-30 µm to determine their complex-valued refractive index N=n+ik. Contact angles for the films were measured with water. The films were exposed to human serum albumin and the adsorption was monitored in-situ using dynamic ellipsometry. From the ellipsometric data the adsorbed amount of proteins was quantified in terms of surface mass density using de Feijters model. The protein layer index was described with a Cauchy model. The results indicate larger adsorption of protein onto the amorphous films compared to the films with more ordered structure.