空间相位调制表面等离子体共振检测蛋白质芯片

Protein chip detection based on spatial phase modulation surface plasmon resonance

蛋白质组学研究需要无标记高通量的检测技术。将空间相位调制与表面等离子体共振传感结合,使生物分子相互作用引起的反射光的相位变化转换成干涉条纹的移动,通过计算条纹的位移可得到相位的变化量,解析出相关的蛋白质相互作用信息。实验结果表明:系统的相位分辨率为0.2°,可检测出质量分数为0.02%的食盐溶液,相当于3×10-5RIU(refractive index unit)的折射率分辨率。适当增加传感芯片上金膜的厚度,可将折射率分辨率提高到2×10-6RIU。兔IgG与羊抗兔IgG相互作用实验又进一步表明:该系统具有实时阵列检测蛋白质相互作用的能力,进一步提高精度并完善后可成为蛋白质组学研究的重要工具。

Proteomics research needs a label-free high throughput detection technique. This paper presents a surface plasmon resonance interferometer based on spatial phase modulation. In this system, the phase change of the reflected light caused by the biomolecular interactions is converted to the interference stripe displacement, with the information on the biomolecular interactions then obtained by calculating the displacement. The results show that the system has a phase resolution of 0. 2°, which can detect NaC1 solutions with NaCl mass fractions as low as 0.02%, equivalent to a refractive index resolution of 3 × 10^-8RIU （refractive index unit）. The resolution can be further increased to 2× 10^-6 RIU by increasing the gold film thickness of the sensing chip by several nanometers. Experimental analyses of rabbit IgG/goat-anti-rabbit IgG interactions indicate that the system can detect array protein interactions in real time.