AVS 50th International Symposium
    Biomaterial Interfaces Friday Sessions
       Session BI+PS-FrM

Paper BI+PS-FrM6
PECVD Growth and Ion Beam Modification of Polymer Films with Patterned Surface Charge Properties

Friday, November 7, 2003, 10:00 am, Room 318/319

Session: Plasma Methods for Bio-interfaces
Presenter: A. Valsesia, Joint Research Centre, Ispra, Italy
Authors: A. Valsesia, Joint Research Centre, Ispra, Italy
M. Manso, Joint Research Centre, Ispra, Italy
G. Ceccone, Joint Research Centre, Ispra, Italy
D. Gilliland, Joint Research Centre, Ispra, Italy
F. Rossi, Joint Research Centre, Ispra, Italy
Correspondent: Click to Email
The performance of polymer films in biomedical devices such as DNA arrays and other biosensors depends greatly on the ability to control their surface properties. In fact, surface features determine the ability of the polymer to immobilize a target biomolecule or to give this molecule an orientation towards adsorption. Plasma enhanced chemical vapor deposition (PECVD) of Polymers is an attractive way to produce this kind of films due to the high rate of functional groups obtained at energies ensuring film stability. The density of functional groups can be modified by an Ion Beam Modification. If this last treatment is performed through a mask, the surface remains with regions expressing different responses to chemical groups and environmental free charges (i.e. ions in solution). In this work we have studied the properties of two polymers with contrasted surface charge behavior. Allylamine (AlA) and Acrylic Acid (AcA) films were studied in parallel by Fourier transformed infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) outlining the changes occurred during plasma polymerization and ion beam modification. These spectroscopic results were correlated with wetting and surface charge behavior by performing contact angle and Z-potential measurements. Their stability and ability for protein adsorption was evaluated by using a quartz crystal microbalance (QCM-D). The possible interference with topographic features has been tested by observing the films in an atomic force microscope, which was further used to monitor electric fields in buffer solutions. From these results we conclude that the combination of PECVD and ion beam modification is an effective way for the growth of polymer films with controlled properties for bio-sensing applications.