A surface plasmon resonance imaging interferometry for protein micro-array detection

A kind of common-optical-path SPR imaging interferometry for micro-array detection is presented. It is a combination of SPR and spatial phase modulation measurement. In this method, the SPR sensing chip surface is illuminated with collimated parallel light beam, and a Wollaston prism is introduced into the reflected light path to produce the interference of polarized light reflected from SPR sensing chip. The p-polarization and s-polarization lights serve as measurement and reference beam, respectively. The information of biochemical reactions can be obtained by extracting the phase change from the SPR interference patterns. As a common-optical-path interferometry, it can reduce disturbances from the ambient conditions. Furthermore, this method is competent for real-time array detection. Various solution concentration and antigen–antibody interaction have been measured with this method. The experiment results indicate that the method can detect micro-array chips in real time. It opens up a new avenue for high-throughput SPR micro-array phase detection, which will benefit the drug discovery and proteomics study.