Preparation of oleylethylene glycol-sreptavidin surfaces for SPR v2

Surface plasmon resonance uses gold surfaces for sensing. Manufacturers provide a range of pre-functionalised surfaces, but these are often prone to non-specific binding problems. In other surface science sensing techniques a range of surface functionalisation approaches have been described. Here, the preparation of a self-assembled monolayer (SAM) of a thiolated oleyl ethylene glycol, incorporating a defined mole % of biotinylated ligands , on a gold surface is described. This allows the formation of a streptavidin layer on the SAM with control over the average surface coverage of streptavidin. Biotinylated ligands can then be immobilised on the streptavidin. Such surfaces have proved to be very resistant to non-specific binding and they are easily implemented on the sensor surfaces of commercial (surface plasmon resonance) SPR instruments. This is adapted from a published method: Migliorini, E. et al. Well-defined biomimetic surfaces to characterize glycosaminoglycan-mediated interactions on the molecular, supramolecular and cellular levels. Biomaterials (2014) doi:10.1016/j.biomaterials.2014.07.017.