Development of Nanoarrayed Surfaces for Improved SPR Detection of Biomolecular Recognition

Sensors based on biomolecular recognition, i.e. biosensors, are very promising tools for the development of advanced analytical devices. Among all techniques available, Surface Plasmon Resonance is a label-free optical technique that allows quantitative analysis in real time and provides outstanding detection performances. The improvement of biosensor performances, such as sensitivity, specificity and cross reaction control, is intrinsically related to the quality of the bio-interface. Bio-interface is the location where the biomolecules interact with the surface and where the biomolecular recognition process occurs. The main challenge is to design a well controlled bio-interface that allows the immobilisation of the bio-probes in an active state to promote efficient biomolecular recognition. A recent promising approach to improve the detection of biomolecular recognition concerns the creation of surfaces with chemical nano-contrasts (for instance adhesives/non adhesives) to reduce steric hindrance and provide a better availability of the binding sites. In this thesis, we describe the fabrication, by plasma colloidal lithography, of nanoarrayed surfaces that induce this effect. Moreover it is shown that an optical enhancement of the signal due to the crystalline geometry of the features creates unique optical characteristics related to surface plasmons excitation. These nanoarrays were applied to SPR detection of several immunoreactions demonstrating that nano-patterned surfaces with optimal geometry improve significantly the SPR detection sensitivity.JRC.DG.I.5-Nanobioscience