Self-referencing SPR imaging for most demanding high-throughput screening applications

Surface plasmon resonance (SPR) imaging emerges as a promising method for label-free real-time observation of biomolecular interactions in highly parallelized format. However, performance of current SPR imaging sensors is rather limited. In this paper, a novel approach to SPR imaging combining measurement in polarization contrast and self-referencing is reported, which delivers an order of magnitude improvement in sensor resolution. This novel SPR imaging sensor is capable of measuring changes in the refractive index of 2 × 10−7 RIU (refractive index unit) or changes in the protein surface coverage below 0.2 pg/mm2 simultaneously in more than a hundred sensing channels.