复旦大学张凡团队报道了具有NIR-II激发和发射的反离子配对明亮七甲川菁荧光团可实现多路生物医学成像。相关研究成果发表在2022年3月16日出版的《德国应用化学》。

NIR-II光谱窗口的光子激发和发射实现了高对比度深层组织生物成像。然而，具有NIR-II激发和发射的多路成像受到了有限化学策略的阻碍，该策略旨在开发在该光谱区域具有可调谐吸收的明亮荧光团。

该文中，研究人员通过物理有机方法开发了一系列七甲川菁（HCs），其吸收/发射最大值从1100到1600 nm不等。研究发现，与HCs配对的大体积反离子能显著改善水中的吸收率（7倍）、亮度（14倍）和光谱分布，解决了因聚集和极化导致的NIR-II菁的猝灭问题。研究人员展示了HC1222和HC1342在1120nm和1319激发下对活体小鼠的循环系统、淋巴结构、肿瘤和器官功能进行高对比度双色成像的实用性，使HCs成为一个有希望的非侵入性生物成像平台。

附：英文原文

Title: Counterion-paired Bright Heptamethine Fluorophores with NIR-II Excitation and Emission Enable Multiplexed Biomedical Imaging

Author: Yang Yang, Caixia Sun, Shangfeng Wang, Kui Yan, Mengyao Zhao, Bin Wu, Fan Zhang

Issue&Volume: 2022-03-16

Abstract: Photon excitation and emission at the NIR-II spectral window enable high-contrast deep-tissue bioimaging. However, multiplexed imaging with NIR-II excitation and emission has been hampered by the limited chemical strategy to develop bright fluorophores with tunable absorption in this spectral regime  . Herein, we developed a series of heptamethine cyanines (HCs) with varied absorption/emission maxima spanning from 1100 to 1600 nm through a physical organic approach. A bulky counterion paired to HCs was found to elicit substantial improvements in absorptivity (7-fold), brightness (14-fold), and spectral profiles in water, addressing a notorious quenching problem of NIR-II cyanines due to aggregation and polarization. We demonstrated the utilities of HC1222 and HC1342 for high-contrast dual-color imaging of circulatory system, lymphatic structures, tumor, and organ function in living mice under 1120 nm and 1319 excitation, enabling HCs as a promising platform for non-invasive bioimaging.

DOI: 10.1002/anie.202117436

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202117436