单分子定位超分辨显微成像有机荧光探针的研究进展

In the biomedical field, it is of great significance to conduct research on the precise positioning of micro-biological targets at the nanoscale level, and optical microscopic imaging technology provides a powerful tool for this. Limited by the optical diffraction limit, optical microscopic imaging technology has difficulty in resolving biological structures with a size below the diffraction limit (< 200 nm), and cannot directly obtain information about micro-biological structures, which hinders the further development of biomedicine. In recent years, with the emergence of nano-resolution microscopic imaging technology, the development of new fluorescent probes, the continuous development of imaging systems and equipment, and the in-depth combination of continuously improved imaging algorithms have promoted the research on microscopic targets with a size below the optical diffraction limit. Super-resolution fluorescence microscopic imaging based on single-molecule localization (SMLM), including photoactivated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM), closely combines organic fluorescent probes with super-resolution optical microscopic imaging technology. The photophysical properties of fluorescent probes directly determine the quality of super-resolution imaging results. Therefore, designing fluorescent probes with different properties can achieve different super-resolution imaging of ultra-fine structures, providing a powerful tool for studying their biological functions. This article focuses on summarizing and reviewing aspects such as the principles based on SMLM, the design requirements of organic fluorescent probes, the types of fluorescent probes used for SMLM and their biological applications, points out the deficiencies in single-molecule localization imaging, and looks forward to its development direction, hoping to provide help in imaging theory and probe design for researchers interested in super-resolution imaging research or those who are new to this field.

在生物医学领域,对纳米尺寸级别的微小生物目标进行精确定位研究具有非常重要的意义,而光学显微成像技术为此提供了强有力的工具.光学显微成像技术受到光学衍射极限的限制,难以分辨尺寸在衍射极限( < 200 nm)以下的生物结构,无法直接获取微小生物结构信息,阻碍了生物医学的进一步发展.近年来,随着纳米分辨显微成像技术的出现,新型荧光探针的开发、成像系统与设备的不断发展及成像算法不断完善地深入结合,促进了光学衍射极限以下尺寸微观目标的研究.基于单分子定位的超分辨荧光显微成像( SMLM)包括光激活定位成像( PALM)与随机光学重构超分辨成像( STORM),将有机荧光探针与超分辨光学显微成像技术紧密结合在一起,荧光探针的光物理性质直接决定着超分辨成像结果的好坏.因此,设计不同性能的荧光探针可以实现超精细结构的不同超分辨成像,为研究其生物学功能提供了有力的工具.本文着重围绕基于SMLM的原理、有机荧光探针的设计要求、用于SMLM的荧光探针种类及其生物应用等方面进行总结综述,指出了单分子定位成像上存在的不足,并对其发展方向进行了展望,希望为对超分辨成像研究感兴趣或初涉该领域的研究者提供成像理论与探针设计方面的帮助.