提高角度法SPR检测系统分辨率的方法

Improved resolution for SPR detection systems with angular modulation

提高表面等离子共振(surface plasmon resonance,SPR)检测系统的分辨率有利于扩大其应用。该文围绕角度检测方法,从理论上阐明了检测系统的分辨率不仅随着灵敏度的增强而改善,而且随着半峰宽的变窄而提高。同时,深入分析了使用金、银以及金银膜的分辨率,明确金银膜的分辨率比金膜高,提出采用金银膜的芯片来提高系统的分辨率。以不同质量分数的NaCl溶液为介质,分别测量使用金膜和金银膜时的分辨率。实验结果表明,金膜和金银膜各自对应的分辨率为5.2×10-6 RIU(refractive index unit)和3.9×10-6 RIU,后者较前者提高1.4倍,与理论分析结果 1.6倍接近。

Improved system resolutions for surface plasmon resonance （SPR） will enable applications in more fields. This paper shows theoretically that the resolution of SPR with angular modulation is not only improved with increased sensitivity, but also with a narrower half-peak width. The resolutions with Au, Ag and Au-Ag chips show that the resolution of the Au-Ag chip is higher than that of the Au chip. Thus, the system resolution can be improved by using the Au-Ag chip. Measurements of the resolution of Au and Au-Ag chips using NaCI solutions with different mass fractions show that the Au and Au-Ag chip resolutions are 5.2 × 10^- 6 and 3.9 × 10^-6 RIU （refractive index unit）. Thus, the Au-Ag chip resolution is 1.4 times higher than the Au chip, similar to the theoretical result being 1, 6 times higher.