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-MoP3
The Silanisation of Tantalum Pentoxide for Biosensor Realisation

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

Session: Biorecognition Poster Session
Presenter: W. Laureyn, IMEC, Belgium
Authors: W. Laureyn, IMEC, Belgium
F. Frederix, IMEC, Belgium
A. Campitelli, IMEC, Belgium
J.-J. Pireaux, FUNDP, LISE, Belgium
G. Maes, KULeuven, Belgium
Correspondent: Click to Email
Affinity biosensors allow the detection of affinity based interactions between bio-molecules, which occur e.g. in antibody-antigen recognition or DNA hybridisation. The presence of antigens in an analyte can be verified by the binding of these molecules to their complementary antibodies, immobilised onto a biosensor surface. Tantalum pentoxide is considered as a material with unique properties for biosensor realisation, being chemically very stable and attractive from an electronic point of view, owing to its high dielectric constant. In order to realise tailored bio-interfaces; bromoalkyltrichlorosilanes were deposited on Ta@sub2@O@sub5@. The use of chlorosilanes (as opposed to alkylethoxysilane derivatives) leads to the formation of reproducible and close-packed monolayers on the oxide surface. To allow antibody binding, the bromo-functionality was converted into a carboxyl-functionality, via a one step reaction with mercaptoacetic acid. XPS, FT-IR, contact angle goniometry, cyclic voltammetry and impedance measurements were applied for the characterisation of the cleaning of Ta@sub2@O@sub5@, its silanisation and of the demanded surface reaction. The results of this study indicate the success of our approach. Moreover, distinct differences are revealed for (mixed) silane monolayer formation with short or long-chain chlorosilanes, from the liquid or vapour phase. In future work, the use of bromoalkyltrichlorosilanes will be compared to the silanisation of Ta@sub2@O@sub5@ with allylalkyltrichlorosilanes, followed by an oxidation in order to generate carboxyl groups. This procedure will also allow the immobilisation of antibodies on Ta@sub2@O@sub5@.