Title: Holographic chemical sensors based on molecularly imprinted polymers as recognition elements.
Author: Yannick FUCHS
National thesis number: 2012COMP2037
- Molecularly imprinted polymers (MIPs) are tailor-made synthetic receptors capable of specifically recognizing a target molecule. They are synthesized by polymerization of a complex between functional monomers and a template molecule in the presence of cross-linkers. After polymerization and removal of the template molecule, the cross-linked polymer network contains cavities that are complementary to the template in terms of size, shape, and position of functional groups, allowing the polymer to bind target analytes with high affinity and specificity.The work reported in this thesis is focused on the development of MIP-based holographic sensors, a novel group of optical sensors in which MIPs is used as recognition element, and the holographic element is built into it and used as an optical transducer. Label-free binding assays performed with holographic sensors showed the optical signal being specifically modified upon incubation in testosterone solutions. This is due to structural modifications that occur in the MIP matrix upon analyte binding, which consequently give rise to structural changes. Testosterone concentrations as low as 1 µM could thus be detected. The combination of holographic transducers with MIPs as synthetic recognition elements has the potential to give rise to inexpensive general sensing devices that can be adapted to, and used in, a broad range of sensing tasks, without the need of labeling the analyte. These range from the highly sensitive spectrometric sensor to the instrument-less test strip, and should be of interest for industry, biomedical, environmental and food, end even for household use.