Xu Liping, Luo Lan, Wu Hao, Luo Zhengchun, Zhang Zhiyou, Shi Haofei, Chang Tianying, Wu Peng, Du Chunlei, Cui Hong-Liang
College of Instrumentation and Electrical Engineering, Jilin University, Changchun, Jilin 130012, China.
Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science, Chongqing 400714, China.
ACS Sens. 2020 Aug 28;5(8):2398-2407. doi: 10.1021/acssensors.0c00346. Epub 2020 Jul 16.
A novel combination of surface plasmon resonance (SPR) and weak value amplification (WVA) is employed to measure the optical rotation angle and refractive index of chiral enantiomers such as sugars and amino acids. An extremely low optical rotation change (2.73 × 10 rad) is readily measurable, with a resolution of 6.75 × 10 rad, 1 order of magnitude higher than that obtained using weak value amplification with intensity modulation, and a refractive index change of 1.13 × 10 RIU is also detected, with a resolution of 1.99 × 10 RIU, a nearly 1-order-of-magnitude increase in sensitivity over weak measurement based on a Mach-Zehnder interferometer. The optical activity and refractive index changes of chiral molecules are determined in real time by measurements of the output light intensity variation, whereby the absolute configuration of the chiral molecule is identified through the relation between intensity and molecular orientation. The SPR-WVA combination sensing scheme fills the gap of capability for detecting the optical activity of a molecular solution, which has not been possible with conventional SPR alone.
采用表面等离子体共振（SPR）和弱值放大（WVA）的新型组合来测量手性对映体（如糖和氨基酸）的旋光角和折射率。极易测量到极低的旋光变化（2.73×10弧度），分辨率为6.75×10弧度，比使用强度调制的弱值放大获得的结果高1个数量级，并且还检测到1.13×10 RIU的折射率变化，分辨率为1.99×10 RIU，与基于马赫 - 曾德尔干涉仪的弱测量相比，灵敏度提高了近1个数量级。通过测量输出光强度变化实时确定手性分子的旋光性和折射率变化，从而通过强度与分子取向之间的关系识别手性分子的绝对构型。SPR - WVA组合传感方案填补了检测分子溶液旋光性能力方面的空白，这是传统SPR单独无法实现的。
