AVS 52nd International Symposium
    Biomaterial Interfaces Tuesday Sessions
       Session BI1-TuA

Paper BI1-TuA5
Increasing Immunosensor Responses: from Antibody Fragments and 3D Substrates to Functionalized Nanoparticles

Tuesday, November 1, 2005, 3:20 pm, Room 311

Session: Sensors/Diagnostics
Presenter: K. Bonroy, IMEC and K.U. Leuven, Belgium
Authors: K. Bonroy, IMEC and K.U. Leuven, Belgium
F. Frederix, IMEC, Belgium
P. Cliquet, R.U. Gent, Belgium
G. Reekmans, IMEC, Belgium
H. Jans, IMEC, Belgium
T. Ghoos, IMEC, Belgium
R. De Palma, IMEC, Belgium
W. Laureyn, IMEC, Belgium
B. Goddeeris, K.U. Leuven and R.U. Gent, Belgium
P. Declerck, K.U. Leuven, Belgium
G. Borghs, IMEC, Belgium
Correspondent: Click to Email
Researchers are continuously seeking for new transduction principles and biosensor interfaces. Both the transducer and biochemical interface contribute to the sensor signal. However, over the years it became clear that a lot of these approaches lack sensitivity for some applications. In this paper we report on several modifications at the (bio)chemical interface in order to increase/tune the immunosensor signal. Two important routes were investigated; the increase of the amount of active/well-oriented receptormolecules on the surface and the use of functional nanoparticles for signal amplification. In this paper we present some of our approaches to control the amount of immobilized molecules and to mitigate non specific adsorption of proteins. Different mixed thiol SAMs, indirect assay formats, immobilization methods, 3D nanoparticle films, 3D porous gold surfaces, and size-reduced receptormolecules such as ScFvs and Fab antibody fragments were optimized, characterized and their influences on the sensor response were evaluated. We will show that some of these modifications at the level of the interface can generate a considerable increase in the response of immunosensors such as SPR, QCM and electrochemical sensors. In addition, we also optimized some of the above-mentioned enhancement approaches towards one application i.e. antibiotic detection. Therefore, a new antibiotic modified disulfide was synthesized and evaluated on gold substrates and nanoparticles. The characterization and optimization was performed using XPS, SPR, IR, CA, CV and TEM. The antibiotic tailored surfaces and nanoparticles were also evaluated in the final biosensing application. In conclusion, we will show that (bio)chemical modifications of the immunosensor interface can be used to manipulate and control the final sensor signal. In addition, we will show that interface modifications could offer a platform from which application-specific sensitivity problems can partially be addressed.