Discovery of BODIPY J-aggregates with absorption maxima beyond 1200 nm for biophotonics

Xiaoqing Wang; Zhiyong Jiang; Zhaolun Liang; Tianzhu Wang; Yuncong Chen; Zhipeng Liu

doi:10.1126/sciadv.add5660

Discovery of BODIPY J-aggregates with absorption maxima beyond 1200 nm for biophotonics

Sci Adv. 2022 Dec 2;8(48):eadd5660. doi: 10.1126/sciadv.add5660. Epub 2022 Dec 2.

Authors

Xiaoqing Wang¹, Zhiyong Jiang^{2

3}, Zhaolun Liang², Tianzhu Wang², Yuncong Chen³, Zhipeng Liu^{1

2

4}

Affiliations

¹ College of Science, Nanjing Forestry University, Nanjing 210037, China.
² College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China.
³ State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
⁴ Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China.

Abstract

Organic dyes with absorption maxima in the second near-infrared window (NIR-II; 1000 to 1700 nm) are of great interest in biophotonics. However, because of the lack of appropriate molecular scaffolds, current research in this field is limited to cyanine dyes, and developing NIR-II-absorbing organic dyes for biophotonics remains an immense challenge. Here, we rationally designed an ethenylene-bridged BODIPY scaffold featuring excellent J-aggregation capabilities and revealed that the bridging ethylene unit is crucial for intermolecular J-coupling regulation. By integrating the electron-donating groups into the scaffold, we obtained a BODIPY dye, BisBDP2, with a J-aggregate absorption maximum of around 1300 nm. BisBDP2 J-aggregates show excellent photothermal performance, including intense photoacoustic response, and a high photothermal conversion efficiency value of 63%. In vivo results demonstrate the potential of J-aggregates for photoacoustic imaging and photothermal ablation of deep-seated tumors. This study will speed up the exploration of NIR-II-absorbing J-aggregates for future biophotonic applications.