At the core of the biosensor is a photonic chip, which due to the low cost requirements of Point of Care applications is to be fabricated from nano-composite polymeric materials, using highly scalable nano-imprint-lithography (NIL).
The optical properties of the polymers are defined by the nature of the nano-particles included within them; the use of metal oxides allows the modification of refractive index required to optimise the inherent sensitivity of the biosensor.
The photonic crystal optical circuitry used to route light around the chip, and interact it with the medium being sensed, is defined via arrays of features of the order 100 nm in size. Optimisation of the nano-composite polymers for both inherent optical properties and processability via NIL presents a significant challenge, which the P3SENS consortium has tackled head on.
A range of polymer host materials and nano-particles have been screened to identify suitable systems for the formation of nano-composites and subsequent processing via NIL. It has been shown that the refractive index of the polymer can be increased significantly by the incorporation of the correct nano-particles. Thin films (below 500 nm) of polymeric materials with a refractive index of up to 1.74, have been prepared. Moreover, initial tests indicate that the high index nano-composites can be structured by NIL.
The completion of these significant milestones, showing development of new materials suitable for the production of polymer photonic crystals, is rapidly leading the P3SENS consortium towards its goal to produce a biosensor platform and demonstrate applicability in the Point of Care diagnosis of Stroke. The consortium continues its multidisciplinary approach with parallel activities driving forward development in polymer materials, photonic crystal fabrication, optical and fluidic systems, and biomedical proteomics.
P3SENS
