In the past decade, fluorescence bioimaging in the second near-infrared (NIR-II, 1000–1700 nm) window has shown great potential in both fundamental research and preclinical diagnosis and prognosis, owing to high resolution at deep penetration and decreasing light absorption and scattering. Compared to inorganic contrast agents, NIR-II organic dyes are more promising for biological application due to low molecular mass, good biocompatibility, and flexible molecular design. In this review, current chemical structures and applications of NIR-II organic dyes (polymethine dyes and donor–acceptor–donor dyes) are discussed. In addition, rational design strategies for NIR-II organic dyes, including conjugated chain length, chain length alternations, charge transfer between terminal groups, rigid plane chemical structure, and other factors, are summarized. This review may provide guidance for further development of novel NIR-II organic dyes for bioimaging and biosensing.

中文翻译：

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用于生物成像和生物传感的近红外II有机分子染料的合理设计

在过去的十年中，由于深度穿透的高分辨率和减少的光吸收，第二个近红外（NIR-II，1000-1700 nm）窗口中的荧光生物成像在基础研究以及临床前诊断和预后方面均显示出巨大潜力。散射。与无机造影剂相比，NIR-II有机染料具有分子量低，生物相容性好和分子设计灵活的特点，因此在生物应用方面更具前景。在这篇综述中，讨论了NIR-II有机染料（聚次甲基染料和施主-受主-施主染料）的当前化学结构和应用。此外，总结了NIR-II有机染料的合理设计策略，包括共轭链长，链长交替，端基之间的电荷转移，刚性平面化学结构和其他因素。