An array detection biosensor based on surface plasmon resonance interferometric imaging

A novel Surface Plasmon Resonance (SPA) array biosensor based on interferometric imaging is presented. In traditional SPR imaging, the fluctuation and non-uniform distribution of light intensity are the main obstacles to achieving a high resolution, especially for SPA array detection. To eliminate the light intensity fluctuation and obviate background correction, a new index normalized signal, which is calculated from sequential images with pi/2 and -pi/2 phase shifts added alternately by an Electro-Optical crystal, is proposed. Refractometry experiment results demonstrate a noise-limited refractometric bulk resolution of about 2 x 10(-6) RIU. Biomolecular interaction experiments suggest this new SPA biosensor is suitable for high-throughput array detection. This SPA array biosensor, immune from light error, offers considerable higher efficiency and is competent for real time biological research and drug development.