Stable, Wavelength‐Tunable Fluorescent Dyes in the NIR‐II Region for In Vivo High‐Contrast Bioimaging and Multiplexed Biosensing

Abstract

Small-molecule organic fluorophores,s pectrally active in the 900-1700 nm region, with tunable wavelength and sensing properties are sought-after for in vivo optical imaging and biosensing. Apanel of fluorescent dyes (CX)has been developed to meet this challenge. CX dyes exhibit the wavelength tunability of cyanine dyes and have ar igidified polymethine chain to guarantee their stability.They are chemoand photo-stable in an aqueous environment and have tunable optical properties with maximal absorbing/emitting wavelength at 1089/1140 nm. They show great potential in highcontrast in vivo bioimaging and multicolor detection with negligible optical cross talk. Fçrster resonance energy transfer (FRET) between CX dyes was demonstrated in deep tissue, providing an approach for monitoring drug-induced hepatotoxicity by detection of OONO À .T his report presents as eries of NIR-II dyes with promising spectroscopic properties for high-contrast bioimaging and multiplexed biosensing.

A facile way to obtain near-infrared room-temperature phosphorescent soft materials based on Bodipy dyes

“…[27][28][29][30][31] Materials with absorption in the visible region and emission in the NIR region are promising candidates in a wide range of elds, such as medical and therapeutic applications, due to their high tissue penetration and low autouorescence. [32][33][34][35] Up till now, materials with NIR RTP emission have been essentially limited to metal complexes like Pt and Ir, which suffer from complicated synthesis, high cost and biotoxicity. [36][37][38] Therefore, it's desirable and worthwhile to develop pure organic phosphors with NIR phosphorescence emission.…”

An IR820 Dye–Protein Complex for Second Near‐Infrared Window and Photoacoustic Imaging

“…In particular, organic fluorophores such as CH1055, which is based on a donor–acceptor–donor structure including a benzobisthiadiazole derivative as the acceptor, demonstrate attractive optical properties (NIR‐II emission spectra, good quantum yield, high photostability) and excellent in vivo performance . Polymethine fluorophores with NIR‐II emission have also been reported . However, these highly novel organic fluorophores suffer disadvantages such as complicated synthesis, low solubility in aqueous solution, and low availability.…”

Engineered Near‐Infrared Fluorescent Protein Assemblies for Robust Bioimaging and Therapeutic Applications

“…Due to the reduced photon scattering and minimal tissue absorption, fluorescence imaging in the NIR window (700–1700 nm) offers increased tissue penetration depths and a better signal‐to‐noise ratio rendering it ideal for biomedical applications. [ 1–7 ] Currently, NIR fluorescent materials mainly comprise quantum dots, [ 8–10 ] lanthanide‐doped upconverting nanoparticles, [ 11–13 ] organic small molecules, [ 14,15 ] and polymer‐based systems. [ 16 ] However, long‐term toxicity and immunogenicity, non‐biodegradability, as well as photo‐instability of these non‐life‐like materials have restricted their translation into clinical applications.…”