Abstract: Combining surface plasmon resonance (SPR) and spatial phase modulation, a real-time SPR sensing chip was illuminated with a collimated parallel light beam. A Wollaston prism was introduced into the detection light path, causing the p- and s-polarization components to interfere with each other. The information of biochemical reactions could be obtained by extracting the phase change from the interference patterns. The sensor chips, on which the Au film was 30 nm and 40 nm, experimented with 50% and 20% alcohol solutions respectively to obtain SPR array graph. Subsequently, two proteins, rabbit IgG as positive sample and Bovine Serum Albumin (BSA) as negative control, reacted with the mixed solution of 0.2 mL goat-anti-rabbit IgG sample and 1.8 mL deionized water, using Au film of 30 nm. The reaction diagram was also attained. The experimental results indicated that, with the merits of high noise resistance, high sensitivity, unlabelled and real-time detection, this SPR method could meet the requirement of protein micro-array detection.

Key words: Protein micro-array, SPR, Phase detection, Interference of polarized light