Rational Design of NIR-II AIEgens with Ultrahigh Quantum Yields for Photo- and Chemiluminescence Imaging

作者：Shen, Hanchen; Sun, Feiyi; Zhu, Xinyan; Zhang, Jianyu; Ou, Xinwen; Zhang, Jianquan; Xu, Changhuo; Sung, Herman H. Y.; Williams, Ian D.; Chen, Sijie; Kwok, Ryan T. K.; Lam, Jacky W. Y.; Sun, Jianwei; Zhang, Fan^*; Tang, Ben Zhong^*

来源：Journal of the American Chemical Society, 2022, 144(33): 15391-15402.

DOI：10.1021/jacs.2c07443

• AGGREGATION-INDUCED EMISSION
• CARBON NANOTUBES
• VIVO
• FLUOROPHORES
• LUMINOGENS

Fluorescence imaging in the second near-infrared window (NIR-II, 1000-1700 nm) using small-molecule dyes has high potential for clinical use. However, many NIR-II dyes suffer from the emission quenching effect and extremely low quantum yields (QYs) in the practical usage forms. The AIE strategy has been successfully utilized to develop NIR-II dyes with donor-acceptor (D-A) structures with acceptable QYs in the aggregate state, but there is still large room for QY improvement. Here, we rationally designed a NIR-II emissive dye named TPE-BBT and its derivative (TPEO-BBT) by changing the electron-donating triphenylamine unit to tetraphenylethylene (TPE). Their nanoparticles exhibited ultrahigh relative QYs of 31.5% and 23.9% in water, respectively. By using an integrating sphere, the absolute QY of TPE-BBT nanoparticles was measured to be 1.8% in water. Its crystals showed an absolute QY of 10.4%, which is the highest value among organic small molecules reported so far. The optimized D-A interaction and the higher rigidity of TPE-BBT in the aggregate state are believed to be the two key factors for its ultrahigh QY. Finally, we utilized TPE-BBT for NIR-II photoluminescence (PL) and chemiluminescence (CL) bioimaging through successive CL resonance energy transfer and Fo''rster resonance energy transfer processes. The ultrahigh QY of TPE-BBT realized an excellent PL imaging quality in mouse blood vessels and an excellent CL imaging quality in the local arthrosis inflammation in mice with a high signal-to-background ratio of 130. Thus, the design strategy presented here brings new possibilities for the development of bright NIR-II dyes and NIR-II bioimaging technologies.

• 单位
  复旦大学