AVS 51st International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP7
The Use of Novel Self-Assembled Monolayers for Enhancing Biosensor Performance

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: W. Laureyn, IMEC, Belgium
Authors: W. Laureyn, IMEC, Belgium
F. Frederix, IMEC, Belgium
K. Bonroy, IMEC, Belgium
T. Ghoos, IMEC, Belgium
R. De Palma, IMEC, Belgium
K. Jans, IMEC, Belgium
C. Zhou, IMEC, Belgium
G. Reekmans, IMEC, Belgium
P. Declerck, KULeuven, Belgium
W. Dehaen, KULeuven, Belgium
G. Maes, KULeuven, Belgium
C. Van Hoof, IMEC, Belgium
Correspondent: Click to Email
The increasing miniaturisation of biochips and the demand for higher sensor detection sensitivities put severe demands on the process and methodology of coupling biomolecules to surfaces. More specifically, controlled thin film structures have to be created which allow the bio-affinity elements to be arranged and addressed in a reproducible and controlled manner. Addressing these issues, IMEC has developed promising methodologies for the construction of novel, well-defined biosensor interfaces, based on the deposition of Self-Assembled Monolayers (SAMs) of alkane thiols or disulfides on metal (e.g. gold) and alkyltrichlorosilanes on oxide (e.g. tantalum pentoxide) surfaces. In addition, polymeric biosensor interfaces have been created on gold using grafted polysiloxane-g-poly(ethylene glycol) polymers. In order to retain biological activity and to allow for the necessary accessibility, the biomolecular functional units have been immobilised onto gold and oxide surfaces derivatised with mixed SAMs. In the mixed SAM approach, the first molecule carries a functional group to firmly attach the bioreceptor molecule and the second molecule resists the non-specific adsorption of undesired biological entities. Different types of mixed SAMs have been optimised, containing e.g. molecules with a molecular backbone comprised of protein-resistant functionalities and molecules with highly reactive functional moieties. For protein detection, mixed SAMs were optimised in order to increase the amount of receptor molecules (antibodies and fragments) on the surface, while still mitigating non-specific adsorption, allowing for highly sensitive immunosensing in non-specific matrices. For the detection of small molecules, highly reproducible and tuneable immobilization protocols were developed, based on mixed SAMs. The optimisation of these (mixed) SAMs was conducted using various surface characterisation tools and using SPR and QCM-D for immunosensing experiments.