Polymethine‐Based Semiconducting Polymer Dots with Narrow‐Band Emission and Absorption/Emission Maxima at NIR‐II for Bioimaging

• Published in: Angewandte Chemie International Edition Vol. 60; no. 2; pp. 983 - 989
• Main Authors: Liu, Ming‐Ho, Zhang, Zhe, Yang, Yu‐Chi, Chan, Yang‐Hsiang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 11-01-2021
• Edition: International ed. in English
• Subjects: Absorption; Animals; Aqueous solutions; Brain - diagnostic imaging; Contrast Media - chemistry; Density Functional Theory; dyes/pigments; Emission; Fluorescence; Fluorescent Dyes - chemistry; imaging agents; Indoles - chemistry; Infrared Rays; Medical imaging; Medulloblastoma - diagnostic imaging; Mice; Mice, Inbred C57BL; Neuroimaging; Optical Imaging - methods; Polymers; Quantum Dots - chemistry; Semiconductors; Spatial discrimination; Spatial resolution; Spectroscopy, Near-Infrared; Surgery; synthetic methods; dyes/pigments; imaging agents; polymers; fluorescence; synthetic methods
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202011914

Deep‐penetration fluorescence imaging in the second near‐infrared (NIR‐II) window heralds a new era of clinical surgery, in which high‐resolution vascular/lymphatic anatomy and detailed cancerous tissues can be visualized in real time. Described here is a series of polymethine‐based semiconducting polymers with intrinsic emission maxima in the NIR‐IIa (1300–1400 nm) window and absorption maxima ranging from 1082 to 1290 nm. These polymers were prepared as semiconducting polymer dots (Pdots) in aqueous solutions with fluorescence quantum yields of 0.05–0.18 %, and they demonstrate promising applications in noninvasive through‐skull brain imaging in live mice with remarkable spatial resolution as well as signal‐to‐background contrast. This study offers a platform for future design of NIR‐IIa or even NIR‐IIb emitting Pdots.
A novel series of polymethine‐based semiconducting polymers were synthesized for the first time and prepared as Pdots in water with both absorption and emission in the NIR‐II window. These Pdots can be further applied for deep‐tissue non‐invasive fluorescence imaging.