Novel compact architecture for high-resolution sensing with plasmonic gratings in conical mounting

ABSTRACT A novel compact architecture implementi ng grating-coupled surface plasmon resonance (GCSPR ) based on polarization modulation in conical mounting is presented. In this system a plasmonic grating is azimuthally rotated in order to support the excitation of high-sensitivity surface plasmon polaritons (SPPs). At SPP resonance, a scan of the incident polarization is performed before and after the binding event and the phase term of the output trend is exploited as sensing parameter. The mechanical complexity of the SPR system is significantly reduced and a resolution down to 10 -7 refractive index units is assured. In this work a numerical study of the polarization-based grating-coupled SPR technique is performed and analyzed with Chandezon’s method. Therefore an experimental test on an assembled prototype is presented and applied to the detection of binding events on the grating surface (avidin/biotin reaction, DNA/PNA probes). Keywords: surface plasmon resonance, metallic gratings, conical mounting, polarization modulation, sensing, biotin/avidin, PNA, DNA