Substrate Mode-Integrated SPR Sensor

We present the design, implementation and characterisation of an integrated surface plasmon resonance (SPR) biosensor chip involving diffractive optical coupling elements avoiding the need of prism coupling. The integrated sensor chip uses the angular interrogation principle and includes two diffraction gratings and the SPR sensing zone. The theoretical design is presented as well as the fabrication process. Experimental results (response of a reference water droplet and phosphate-buffered saline/water kinetic) are presented and compared with those obtained with the classical Kretschmann prism coupling setup. We believe that this prism-free architecture is perfectly suitable for low-cost and reproducible SPR biochemical sensor chips since the sensing zone can be functionalised as any other one