荧光各向异性（荧光偏振）信号受外界干扰波动小，可实现均相、原位分析。人工合成的功能性核酸既拓宽了生物识别的目标物范围，降低了成本，又使得传感方法简单、易于操作。基于功能性核酸的荧光各向异性传感能够将两者的优势有效的结合，构筑均相、原位、实时、经济、选择性好和灵敏度高的检测方法；由于荧光各向异性测量能提供研究体系丰富的信息，因此也为DNA与兴趣目标物之间的作用研究提供了有力工具，是荧光传感领域的重要方向之一。本项目拟围绕基于功能性核酸的荧光各向异性传感所涉及的基本科学问题开展系统研究，探讨不同结构的DNA转动扩散模式以及荧光团与DNA的相互作用，确定可调控荧光各向异性的参数，拓展Perrin 模型的应用，丰富与发展基于荧光标记核酸的荧光各向异性理论与方法，并在此基础上解决传统各向异性方法对小分子兴趣目标物灵敏度低等问题，构建通用、快速、简单的基于功能性核酸的荧光各向异性传感平台。

Fluorescence anisotropy (also fluorescence polarization) sensing based on functional nucleic acids conducts measurements in a homogeneous analysis manner with high-throughput and in situ analysis capacity, as well as low-cost, sensitive and selective properties, providing a powerful tool for the nucleic acid-target interaction study, drug discovery, biochemical research, clinical diagnosis, and food analysis. Thus, fluorescence anisotropy based on recognition between the functional nucleic acid and the target has attracted great attention and become an important area in the fluorescence biosensing field. This project will focus on basic questions arising from fluorescence anisotropy sensing based on functional nucleic acids, i.e. the physical model for describing rotational diffusion manner of DNA with different structures，the interaction between DNA and the fluorescent label, and the parameters that can be used to modulate fluorescence anisotropy. We hope to expand the application of the Perrin equation in predicting fluorescence anisotropy of fluorescently labeled DNA and to better apply this technique to development of generalizable, simple, and cost-effective sensing platforms, especially for small molecules which have been a challenge in the fluorescence anisotropy sensing field.