In recent life science research,identifying and characterizing entire biomolecular interaction networks is prerequisite to understanding cellular processes on a molecular and biophysical level.A surface plasmon resonance (SPR) imaging interferometer based on spatial phase modulation detection is presented to meet this demand.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.Information of biomolecular interactions can be obtained by extracting the phase change from the SPR interference patterns.Using our interferometer,we made experiments on a series concentration of NaCl solutions to investigate its detection range,linearity,sensitivity and resolution.The results indicate that the SPR imaging interferometer is mainly sufficient for biomolecular interaction detection.
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。
