Self-Reference Surface Plasmon Resonance Biosensor Based on Multiple-Beam Interference

We demonstrated a novel self-reference surface plasmon resonance (SPR) fiber biosensor, which provided a multiple-beam interference referencing signal for refractive index (RI) compensating. The sensor was fabricated by splicing a capillary to a multimode fiber (MMF) coated with a gold film. The gilded MMF acts as the measuring channel while the capillary is used as referencing channel. The experiment result showed that the measuring signal has an irreversible change corresponding specific binding and referencing signal has reversible change. It indicated that the measuring signal can inspect biomolecular interactions in real time and the referencing signal can be used to compensate for interference effects due to bulk RI changes. The sensor provides a high sensitivity of 1470.291 nm/RIU and a resolution about 3.536 × 10 ^-5 RIU. In addition, this self-reference SPR biosensor we proposed is low cost, simple, and reproduction, which can be applied in biochemical sensing field.