Abstract:

In the field of biology and biomedical science, it is of significance to image microscopic targets inside cells with high precision to afford accurate information for diagnosis. Since the emergence of optical microscope, it has been used as a powerful tool to provide precise results, achieving the visualization of tiny objects. However, due to the optical diffraction limit(~200 nm), it is difficult to distinguish the objects less than 200 nm in size, in particular, a lot of significant biological targets with size less than 200 nm in cells, which blocks further advancement of biology science. Recently, with the development of fluorescent probes, imaging system and reconstruction algorithm, superresolution imaging microscopy is emerging as an advanced technique capable of overcoming the limit of optical diffraction, which shows potentials in the study of tiny targets below optical diffraction limit. Among superresolution imaging nanoscopies, single molecule localization microscopies(SMLM), such as photo activation localization microscopy(PALM) and stochastically optical reconstruction microscopy(STORM), show typical advantages over other strategies. Smart fluorescent probes play key roles in PALM/STORM microscopy, of which the photophysical properties typically determine the imaging resolution. Therefore, it is of significance to develop fluorescent probes with excellent optical properties to achieve ultrafine structure imaging of interest inside single cell. In this work, we will mainly focus on recent progress on organic probes for single molecule localization microscopy, including working principles, selection criteria, designing strategies of fluorescent probe and their biological applications. Furthermore, we will also cover on the discussion of the shortcomings remaining to be solved in the future and figure out the possible advancement of SMLM to facilitate the researchers who are interested in or initially step into the area of super-resolution imaging microscopy with theoretical assistance.

Key words: super-resolution imaging, single molecular localization microscopy, fluorescent probe, stochastic optical reconstruction microscopy, photoactivated localization microscopy