Recent advances in luminescent materials for super-resolution imaging: Via stimulated emission depletion nanoscopy

Stimulated emission depletion (STED) nanoscopy is a promising fluorescence microscopy to detect unresolvable structures at the nanoscale level and then achieve a superior imaging resolution in materials science and biological research. However, in addition to the optimization of the microscope, luminescent materials in STED nanoscopy are also of great significance to obtain imaging, visualization and even long-term tracking at an ultra-high resolution (less than 100 nm), but this is seldom summarized. Based on this consideration, recent progress on STED fluorophores for super-resolution imaging is outlined here, including inorganic fluorophores, fluorescent proteins, organic luminescent materials, aggregation-induced emission (AIE) luminogens, and fluorescent nanoparticles. Characteristics of these aforementioned STED fluorophores are also included and compared to provide a deep understanding of the relationship between the properties in luminescent materials and their performance in STED imaging. According to the results on such luminescent materials, it is anticipated that guidelines to select proper probes and even develop new materials for super-resolution imaging via STED nanoscopy will be provided here, finally promoting the development of super-resolution imaging in both materials science and biological research.