SPR Sensor Platform Based on a Novel Metal Bilayer Applied on D-Shaped Plastic Optical Fibers for Refractive Index Measurements in the Range 1.38-1.42

A surface plasmon resonance sensor based on a D-shaped plastic optical fiber and a palladium/gold (Pd/Au) bilayer was designed, implemented, and characterized. The platform was properly thought to work in the 1.38-1.42 refractive index range, where it exhibits excellent performances. This refractive index range is very important when a thin polymer layer is used on the planar metal surface for bio-chemical sensing applications.