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

Abstract

Recent progress on STED fluorophores for super-resolution imaging and also their characteristics are outlined here, thus providing some guidelines to select proper probes and even develop new materials for super-resolution imaging via STED nanoscopy.

Super-Resolution Imaging With Lanthanide Luminescent Nanocrystals: Progress and Prospect

“…In this design, 11,064 nm wavelength as excitation laser and 8% Tm 3+ -doped nanoparticles as fluorescent probes were used to obtain effective photon-avalanche due to the weak ground state absorption and intense excited state absorption. The degree of nonlinearity S can be larger than 20 under a power density below 10 kW/cm 2 , which is two orders of magnitude lower than that used in most STED nanoscopies ( Xu et al, 2021 ). According to Equation 2 , sub-70 nm optical resolution was experimentally achieved under a power density of 7.6 kW/cm 2 .…”

“…Besides, an enhanced resolution (294.4 nm) of single nanoparticle (NaYF 4 : 60%Yb, 8%Er 0.08 @NaYF 4 ) imaging was achieved due to its bright upconversion luminescence ( Ma et al, 2020 ). However, a size distribution of more than 29 nm for these nanoparticles is unsatisfactory for optical super-resolution because a spatial resolution below 30 nm has been achieved through STED nanoscopy ( Xu et al, 2021 ). It is still a great challenge to develop a general synthetic method or nano-architectural method to achieve bright fluorescence intensity from ultrasmall lanthanide-doped nanocrystals with a particle size less than 5 nm ( Willets, 2013 ; Liu et al, 2021 ).…”

Conjugated Polymers: Optical Toolbox for Bioimaging and Cancer Therapy

“…In the last 20 years, great progress has been achieved in imaging probes and nanoparticles. [45][46][47][48][49] Indeed, the hightemporal resolution imaging probes with good sensitivity and biocompatibility are still extremely desirable. Fortunately, CPs were developed as imaging celebrities and elitists in multiple domains of bioimaging due to their excellent optical properties.…”

Aggregation‐Induced Phosphorescent Imaging in the Second Near‐Infrared Window

“…For example, a wide variety of unique AIE systems based on organic chromophores and inorganic metal clusters have been explored intensively, broadening their advanced applications in chemical sensing, bioimaging, and optoelectronics. [6][7][8] More recently, guided by Zn 2+ -controlled AIE mechanism, Hyeon et al [9] reported highly luminescent gold cluster assembly (quantum yield of ≈90% in water) from completely nonluminescent Au 4 clusters. Liu and co-workers applied AIE strategy into the design of organic probe emitting in the second near-infrared window (NIR-II, 1000-1700 nm) and used them for brain-tumor precise imaging.…”