Effect of the transducerʹs surface pre-treatment on SPR aptasensor development

The properties of a transducerʹs surface are crucial in biosensor development since they strongly condition the chemical routes applicable for bioreceptor incorporation and subsequent surface physical blocking. In this way, surface (bio)engineering should provide specificity against the target of choice and minimal non-specific adsorption of non-target components onto the active area of the sensor. The objective of this work was to study the effect of different surface treatments on SPR sensor functionalization and optical performance. We used as a model the well-known thrombin-binding aptamer (TBA), which was incorporated on surface via two different paths: direct selfassembly of thiolated TBA and affinity capture of biotinylated TBA by physisorbed neutravidin. Our results indicate that chip pre-treatment with oxygen plasma produced better transducers than pre-treatment by immersion in organic solvents, piranha or KOH solution, independently of the biofunctionalization strategy used for aptasensor production.