基于相位解算的SPR传感方法及其应用

SPR biosensing method based on phase shift algorithm and its application

提出了一种新颖的基于相位解算的表面等离子体谐振(surface plasmon resonance,SPR)传感方法,该方法包括一种基于振镜扫描的表面等离子体谐振实验装置和通过相位解算来确定谐振角的方法。装置采用振镜驱动入射光束进行角度扫描,避免扇形光束导致的干涉噪声;同时,选择振镜步进式角度扫描,实现完全同步采集数据,抑制采样时钟及扫描速度抖晃引起的相位噪声。相位解算确定谐振角法将衰减全反射(attenuated total reflection,ATR)曲线转换到频域内处理,可有效克服光源噪声对传感测量的干扰,获得高分辨率。实验结果表明,该装置的折射率测量分辨率可达1.8×10-6,线性区间为1.33～1.38,能满足生物学测量的要求。磺胺甲恶唑(sulfamethoxazole,SMX)与其抗体(Anti-SMX)和MSI-78与固体支撑磷脂膜(solid-supported lipid bilayer,SLB)之间反应的检测又进一步证明,该方法在生物医学中具有良好的应用前景。

A novel surface plasmon resonance （SPR） biosensing method based on phase shift algorithm is introduced in this article. This method comprises a galvo scanning based SPR experimental setup and a phase shift algorithm to determine the resonance angle. A galvo scanner is used to drive the incident laser to carry out angle scanning; thus the interference noise caused by the fan-shape light beam can be avoided. Meanwhile, the galvo scanning is performed step by step, and therefore complete synchronous sampling can be achieved to eliminate the phase noise caused by clock and scanning period jitter. In addition, phase shift algorithm is used to determine the resonance angle, which converts the attenuated total reflection （ATR） curve into frequency domain for processing, the interference of the fluctuation and drift of the light source intensity on measurement resuh can be reduced. Experimental results show that a refractivity resolution of 1. 8 × 10^-6 can be achieved with a linear measurement range of 1.33- 1.38, which meets the requirement of biological measurement. Furthermore, SMX/Anti-SMX and MSI- 78/SLB interactions were measured using this method. The results demonstrate that this method has a very good application prospect in biomedical study.