Single Wavelength Laser Excitation Ratiometric NIR-II Fluorescent Probe for Molecule Imaging in Vivo

Abstract

Fluorescence (FL) imaging in the second near-infrared window (NIR-II, 1000–1700 nm) has emerged as a promising bioimaging modality that enables noninvasive visualization of deep tissue with an unprecedented resolution. However, there is a paucity of studies on high-quality responsive NIR-II FL molecules. Herein we report a novel activated NIR-II FL molecule, 4,7-bis­(5-(4-(diphenylamine)­phenyl)-2-thiophene) [1,2,5]­selenadiazolo­[3,4-f]­benzo­[c]­[1,2,5]­thiadiazole (SeTT), which exhibits fast and specific responsive capability to hypochlorous acid (HClO). To obtain the NIR-II ratiometric nanoprobe, SeTT was encapsulated on the surface of Er3+-doped down-conversion nanoparticles (DCNP), achieving the DCNP@SeTT nanoprobe. With a single 980 nm laser excitation, the ratiometric FL signal of SeTT at 1150 nm and DCNP at 1550 nm (I 1150 nm/I 1550 nm) was linearly correlated with the concentration of HClO with a detection limit of 0.4 μM. The ratiometric nanoprobe was successfully investigated for variations in HClO concentration in the tumor progression, visualization of anatomical structures of the peritoneal cavity in the mice model with inflammation, and quantitative detection of the HClO concentration in a rabbit model of osteoarthritis, achieving a fast response and high selectivity for the detection of HClO. The NIR-II-responsive nanoprobe can serve as a promising and effective tool for highly sensitive monitoring and imaging of HClO in living systems.

Molecular Engineering of NIR‐II Fluorophores for Improved Biomedical Detection

“…Reproducedw ith permission.C opyright 2020, American Chemical Society. [68,69] Angewandte Chemie Aufsätze 16440 www.angewandte.de drug-induced hepatotoxicity and hepatic carcinoma mice, respectively.S ignificantly,l ifetime imaging is independent of tissue penetration depth. Therefore,the development of NIR-II FRET-based lifetime probes is an attractive strategy for the detection of targets in deep tissue.…”

“…They are usually stable and not susceptive to reactive species,s uch as HClO,OONO À ,and H 2 O 2 .Incontrast, organic fluorophores are more susceptive to reactive species.T herefore,aratiometric NIR-II probe can be conveniently constructed by incorporating afluorophore into ananoparticle.Usually,they should have overlapping absorption spectra but non-overlapping emission spectra in order to get ar atiometric output with the same excitation. Fore xample,w hen the surface of Er 3+ -doped nanoparticles (DCNPs) is decorated with the fluorophore SeTT (67) [68] or Cy925 (69), [69] an NIR-II ratiometric fluorescent probe for the detection of HClO is fabricated (Figure 6D). Both SeTT and Cy920 react with HClO selectively,which results in fluorescence loss,while the emission of DCNP is not influenced.…”

“…D) Schematic illustration of ratiometric probes fabricated by hybridizing inorganic particles with organic fluorophores SeTT (left) and Cy 925 (right. Reproducedw ith permission.C opyright 2020, American Chemical Society [68,69].…”

Engineering Intelligent Nanosystems for Enhanced Medical Imaging

“…Interestingly, hypochlorite in solution is in equilibrium with hypochlorous acid, which can be detected by yet other ratiometric biosensors. [265,267] For instance, the probe developed by Wang et al was used to detect lymphatic inflammation in mice, and the excitation spectrum in the second NIR window allowed for high spatial resolution ( Figure 11B). [265] The probe can be excited at two wavelengths, one of which is mediated through a hypochlorous acid-degradable dye.…”

Design of ZIF-based hybrid nanoparticles with hyaluronic acid-augmented ROS behavior for dual-modality PA/NIR-II FL imaging

“…[7][8][9] As is well-known, FL imaging can be used to track and visualize diverse uorescent probes without being invasive. 10 Previous FL imaging in the rst near infrared window (NIR-I, 650-900 nm) cannot meet the demands of in vivo imaging with low penetration and high background signals. Compared to NIR-I FL imaging, FL imaging in the second near infrared window (NIR-II, 1000-1700 nm) has advantages of a higher imaging resolution and deeper tissue penetration.…”