Surface Plasmon Resonance Phase-Sensitive Imaging (SPR-PI) Sensor Based on a Novel Prism Phase Modulator

A novel prism phase modulator (PPM) for phase difference modulation between p- and s-polarization lights in a surface plasmon resonance phase-sensitive imaging sensor is proposed in this paper. The PPM consists of a rhombic prism (to obtain a curve of phase difference between the two polarizations), a rotation stage and a mirror. The PPM shows great modulation stability and helps to achieve a high detection resolution. Surface plasmon resonance phase imaging is realized with a microfluidic device and a CCD camera. Experimental result shows that the detection resolution of our SPR-PI sensor based on phase-interrogation method is 7.61 x 10(-7) RIU with hydrous samples, which is 16 times improved compared with that based on intensity-interrogation. Real-time monitoring of the interaction between Angiogenin and anti-Angiogenin is also illustrated.