A novel phase-sensitive surface plasmon resonance (pSPR) biosensor based on differential phase measurement between two cylindrical vector beams, namely radially polarized and azmuthally polarized beams, is proposed and studied in an inverted microscope. Different from a fixed angle or a relatively small angular range for SPR excitation in the attenuated total reflection (ATR) configuration, the signal beam focused by a total internal reflection fluorescence microscopic objective contains the entire angular range from 0 to the maximum angle given by the numerical aperture, leading to a dynamic range of 0.41 RIU which is over seven times wider than the best result of the ATR pSPR sensor. Moreover, with the technique of differential phase measurement between radial and azimuthal polarizations employed in our configuration, high sensitivity of +-9.05 X 10~(-8) refractive index unit/1 deg can simultaneously be achieved in principle. The proposed technique maintains the unique advantages in terms of securing high imaging resolution and sensitivity with an ultra-wide dynamic range simultaneously.
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机译：在倒置显微镜中，提出并研究了一种基于两个圆柱形矢量光束（即径向偏振光束和方位偏振光束）之间相位差测量的新型相敏表面等离子体共振（pSPR）生物传感器。与在衰减全反射（ATR）配置中用于SPR激发的固定角度或相对较小的角度范围不同，由全内反射荧光显微物镜聚焦的信号束包含从0到最大角度的整个角度范围，数字孔径，动态范围为0.41 RIU，是ATR pSPR传感器最佳结果的七倍以上。此外，通过在我们的配置中采用径向和方位极化之间的差分相位测量技术，原则上可以同时实现+ -9.05 X 10〜（-8）折射率单位/ 1度的高灵敏度。所提出的技术在确保高成像分辨率和灵敏度以及超宽动态范围的同时保持了独特的优势。
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