Improving biosensor performance through mathematical modeling (IRO scholarship)

50000403v1642 Promoter: Guy Vandenbosch and Jeroen Lammertyn

details
Description: In nowadays society, food quality and safety are crucial themes. Whereas in industrialized countries, the importance of these issues is considered evident, and consequently the necessary budgets are invested, this is not always possible in the case of developing countries. Easy and cheap detection of directly related phenomena like food allergy, detection of toxins and pathogens, and also cheaper techniques for waste water and soil monitoring would help enormously.
Recently, the MeBioS-Biosensor research group (www.biosensors.be) of prof. Lammertyn has developed an innovative technology based on fiber optic surface plasmon resonance (SPR). The biosensor has a great potential as reusable, cost-effective and label free biosensor for measuring antibody-antigen, DNA hybridization and DNA-protein interactions. This means that this sensor can contribute considerably in the multitude of applications listed above. To this goal, special attention will be paid to design the biosensor - through modeling - as a low cost portable device for ‘in the field’ measurements.
The optical fiber probes are composed of many (bio)nanostructured layers. First the fiber is sputtered with a 50 nm gold layer which is then covered with a protein repulsive self assembled monolayer of mixed polyethylene glycol (PEG). Following streptavidin is attached to the PEG‘s carboxyl groups to serve as a versatile binding element for biotinylated ssDNA or proteins. In a first test the ssDNA coated SPR-fibers were successfully evaluated as a nucleic acid biosensor through a DNA-DNA hybridization assay. In a second assay the fiber optic SPR biosensor was functionalized with ssDNA aptamers as bioreceptor molecules. Finally, antiobody-antigen interactions were studied. The biosensor proved not only to be useful for DNA and protein quantification purposes, but also to reveal the binding kinetics occurring at the sensor surface. Although low limits of detection and quantification are obtained many medical and food diagnostic applications require even lower detection limits. Hereto the fiber optic sensor needs further optimization with respect to the electromagnetic signal transduction.
The fact that the sensor structure is multilayered generates a direct link with the research group ESAT-TELEMIC. Prof. Vandenbosch’s team has developed its own electromagnetic solver, called MAGMAS3D, based on the method of moments, and focusing on arbitrary multilayered structures (see www.esat.kuleuven.be/telemic/antennas/magmas/). MAGMAS3D has taken many years to develop, 5 Ph.D. projects and numerous Master thesis projects. The availability of MAGMAS3D is a unique asset since the source code is available and fully accessible for modification and extension. This is not the case for commercial solvers, where only the executable is available. This means that the MAGMAS3D code can be extended in the direction of new research goals, studying new types of topologies. In principle MAGMAS is applicable in any field of science where electromagnetics is important. The purpose of this PhD. is to adjust, improve and extend the existing MAGMAS software, in close cooperation with the MAGMAS development team, and to apply it for optimization purposes of the abovementioned biosensor configuration. This PhD. work includes both theoretical aspects as well as practical experiments and will be supervised by both promoters.


Key words: electromagnetic modeling, food safety and monitoring techniques, biosensors

Latest application date: 2010-04-30

Financing: iro-scholarship

Type of Position: scholarship

Duration of the Project : 4 years

Research group: Department of Electrical Engineering (ESAT)

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