Spectral and biodistributional engineering of deep near-infrared chromophore

Rigid and Photostable Shortwave Infrared Dye Absorbing/Emitting beyond 1200 nm for High-Contrast Multiplexed Imaging

“…We recently reported a deep-NIR fluorophore (ECYS2). 30 It is a bright fluorophore compatible with the 808 nm laser (Figure 5A). Upon intravenous injection, it undergoes hepatobiliary metabolism and sequentially lights up the liver, biliary tract/ gallbladder, and intestine.…”

“…Two-channel intraoperative fluorescent cholangiography of both the biliary tree and the vasculature is pursued. We recently reported a deep-NIR fluorophore ( ECYS2 ) . It is a bright fluorophore compatible with the 808 nm laser (Figure A).…”

Hypsochromic Shift Donor–Acceptor NIR-II Dye for High-Efficiency Tumor Imaging

“…Theoretically, coupling strong electron-donating groups with strong acceptor groups can ensure efficient NIR-II emission . BODIPY, rhodamine, and cyanine-based D-A NIR-II dyes with good photophysical properties have been developed, showing great potential as NIR-II imaging agents. − However, they always suffer from the problem of poor hydrophilicity, photostability, and fast elimination. , Based on the classical D-A-D dye structure, D-A polymers were also developed with a more significant Stokes shift and better extinction coefficient, but the enormous molecular weight, hard to control degree of polymerization, and the potential long-term retention toxicity limit their clinical transportation. − D-A NIR-II small molecular dyes that reduce one donor group from the D-A-D skeleton have a more simplified structure with a more significant Stokes shift, better photostability, and easier metabolism ability. However, few of these D-A dyes have been reported so far.…”

“…43−48 However, they always suffer from the problem of poor hydrophilicity, photostability, and fast elimination. 49,50 Based on the classical D-A-D dye structure, D-A polymers were also developed with a more significant Stokes shift and better extinction coefficient, but the enormous molecular weight, hard to control degree of polymerization, and the potential long-term retention toxicity limit their clinical transportation. 51−54 D-A NIR-II small molecular dyes that reduce one donor group from the D-A-D skeleton have a more simplified structure with a more significant Stokes shift, better photostability, and easier metabolism ability.…”

Tunable Wavelength, High-Brightness, and NIR-II Emission Phenanthridinium-Based Heptamethine Dyes for High-Contrast Vascular and Intestinal Imaging In Vivo

“…Extending the conjugated structure and increasing structural planarity of a molecule are effective strategies for enhancing photoluminescence quantum yield and prolonging absorption and emission wavelengths. − Building upon previous studies, we discovered that methylated phenanthridone is a great candidate for constructing phenanthridinium heptamethine cyanine. , In addition, the incorporation of electron-donating groups via electrophilic substitution reactions at the 2′ position of phenanthridone can further induce a bathochromic shift. Recently, Ellen M. Sletten and her colleagues synthesized a series of NIR-II flavylium heptamethine dyes by incorporating a secondary amine substituent at the 7’ position of flavylium. ,, Inspired by their work, we selected seven substituents with a gradually increased electron-donating ability to improve the photophysical properties of dyes (Figure ).…”