Surface nanostructuring for Surface Plasmon Resonance imaging

Improving the performances of a sensor is a prominent objective in developing innovative for clinical applications. Sensitivity is key features for a biosensor such applications. An improvement in sensitivity is reported when nanoparticles (NPs) are exploited for functionalizing the interacting surface. In this work an original nanostructure was investigated. Gold nanoparticles are immobilized on a gold surface of a Surface Plasmon Resonance imaging (SPRi) sensor. The surface structuring strategy was studied in its steps, for obtaining a reproducible immobilization of NPs on biochip gold surface. In order to improve our system, we modified SPRi chip with gold NPs attached on the surface trough a dithiol molecule. Further functionalization was achieved using thiolated DNA probes. The possibility to modify the biochip in an array format was really helpful for following the different steps of the procedure. The bioreceptors immobilization protocol was studied following the plasmon curves, confirming the presence of the nanostructure on the biochip surface.