Professor Shengliang Li published a research article in Advanced Materials

Fluorescence bioimaging in the second near-infrared window (NIR-II, 900-1700 nm) has held great promise in the biomedical field over the past decade due to its high resolution, low tissue auto-fluorescence, and deep tissue penetration. Many NIR-II fluorescent materials such as quantum dots, carbon nanotubes, rare-earth doped nanoparticles (NPs), and small organic molecules have been constructed successfully. Among them, conjugated small molecules show extraordinary advantages for in vivo medical diagnostic and phototherapy due to their superior biocompatibility and strong near-infrared (NIR) absorption. However, their practical applications are often retarded by unsatisfactory fluorescence brightness owing to the notorious self-quenching effect.

Recently, Prof. Shengliang Li's group at the College of Pharmaceutical Sciences, Soochow University, published a research paper entitledAnti-Quenching NIR-II J-Aggregates of Benzo[c]thiophene Fluorophore for Highly Efficient Bioimaging and PhototheranosticsinAdvanced Materials. The team reports a J-aggregated fluorophore with an anti-quenching effect for NIR-II imaging of mice blood vessels and in vivo phototheranostics of breast cancer. Upon the 808 nm laser excitation, the whole-body blood vessel of mice can be clearly visualized via NIR-II fluorescence imaging beyond 1300 nm. In addition, the mice tumor tissue can be efficiently eliminated upon one-time irradiation under precise NIR-II imaging guidance. This work paves the way for constructing bright NIR-II emitting J-aggregates for biomedical applications. Corresponding authors include Prof. Shengliang Li, Prof. Ken-Tsung Wong from National Taiwan University, and Prof. Chun-Sing Lee from the City University of Hong Kong.

In this work, a small molecule BT6 was developed to achieve long-wavelength and bright emission after forming water-dispersible nanoparticles (BT6 NPs). The BT6 NPs show intriguing J-aggregation characters, which showed an apparent red shift of absorption and emission compared to the monomer. More importantly, the fluorescence emission is boosted after assembling, which showed an aggregation-induced emission effect. Integrated with large Stokes shift over 400 nm, the BT6 NPs possess the anti-quenching ability and show great potential for in vivo biomedical applications. This work develops a strategy to construct bright NIR-II J-aggregates with precisely manipulated anti-quenching properties for highly efficient biomedical applications.

Figure 1.Schematic illustration of BT molecules design and J-type BT6 NPs for phototheranostics.

Reference:Ka-Wai Lee, Yijian Gao, Wei-Chih Wei, Ji-Hua Tan, Yingpeng Wan,* Zhe Feng, Yuhuang Zhang, Ying Liu, Xiuli Zheng, Chen Cao, Huan Chen, Pengfei Wang, Shengliang Li,* Ken-Tsung Wong,* Chun-Sing Lee,* Anti-Quenching NIR-II J-Aggregates of Benzo[c]thiophene Fluorophore for Highly Efficient Bioimaging and Phototheranostics.Advanced Materials2023, 2211632.

Link:https://doi.org/10.1002/adma.202211632