A New Generation of NIR‐II Probes: Lanthanide‐Based Nanocrystals for Bioimaging and Biosensing

Abstract

Fluorescence‐based imaging in the second near infrared window (NIR‐II, 1000–1700 nm) is extensively used in both fundamental scientific research and clinical practice, owing to its advances of high sensitivity and high spatiotemporal resolution with increasing tissue penetration depths. Among several NIR‐II fluorophores, recent accomplishments in biocompatible lanthanide‐based luminescent nanomaterials have aroused great interest of researchers. This progress report summarizes recent progress in controlled synthesis of lanthanide‐based NIR‐II nanomaterials and their state‐of‐the‐art in NIR‐II biomedical imaging and biosensing applications. In addition, challenges and opportunities for this kind of novel NIR‐II nanoprobes are also discussed.

Rational design of a multifunctional molecular dye for dual-modal NIR-II/photoacoustic imaging and photothermal therapy

“…18,19 Over the past several years, uorescence based imaging in the second near-infrared channel (NIR-II, 1000-1700 nm) has gained attention for its prominent merits and surpasses the conventional visible/NIR-I channels (700-900 nm) in terms of lower tissue scattering and minimal auto-uorescence, thus leading to signicant advances in imaging qualities including image depth and spatiotemporal resolution. [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] More recently, based on a benzobisthiadiazole (BBTD) acceptor, a series of small molecular dyes with a donor-acceptor-donor (D-A-D) architecture have been developed. The reduced energy gap between the hybridized highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels in these molecular systems shied the uorescence emission spectrum from the NIR-I region to the NIR-II channel.…”

Emerging Low‐Dimensional Nanoagents for Bio‐Microimaging

“…[75] It is worth mentioning that fluorescence imaging in the second near-infrared window (NIR-II, 1000-1700 nm) has become a research hotspot in recent years due to its deep tissue penetration and high spatial resolution. [76] Take rare-earth ion doped NaREF 4 nanoparticles, for example; [75] Reproduced with permission. [75] Copyright 2019, Nature Publishing Group.…”

Recent progress in the imaging detection of enzyme activitiesin vivo

“…Fluorescence imaging in the NIR-II region (wavelength 1000-1700 nm) may be more desirable over traditional NIR-I imaging owing to its deeper tissue penetration, reduced photon scattering and lower autouorescence even though it has some problems, such as poor biocompatibility and low uorescence quantum yields, which limit its application for in vivo imaging with enough resolution. [69][70][71] Over the years, several classes of uorescent NIR-II probes, such as carbon nanotubes, small molecules, Ag2S dots and polymers, have been developed for NIR-II uorescence imaging for diversied biomedical applications. [72][73][74][75] In general, the use of NIR uorescent probes for improving the effectiveness of enzyme activity imaging in deeper tissues is only in its infancy, and future years should see an increase in the use of these types of uorescent probes with newer optical approaches, such as optical coherence tomography (OCT) and diffuse optical tomography.…”