In vivo imaging using shortwave infrared (SWIR) light (1,000–2,000 nm) benefits from deeper penetration and higher resolution compared with using visible and near-infrared wavelengths. However, the development of biocompatible SWIR contrast agents remains challenging. Despite recent advancements, small-molecule SWIR fluorophores are often hindered by their significant hydrophobicity. We report a platform for generating a panel of soluble and functional dyes for SWIR imaging by late-stage functionalization of a versatile fluorophore intermediate, affording water-soluble dyes with bright SWIR fluorescence in serum. Specifically, a tetra-sulfonate derivative enables clear video-rate imaging of vasculature with only 0.05 nmol dye, and a tetra-ammonium dye shows strong cellular retention for tracking of tumor growth. Additionally, incorporation of phosphonate functionality enables imaging of bones in awake mice. This modular design provides insights into facile derivatization of existing SWIR fluorophores to introduce both solubility and bioactivity toward in vivo bioimaging.

 与使用可见光和近红外波长相比，使用短波红外 （SWIR） 光 （1,000–2,000 nm） 进行体内成像具有更深的穿透力和更高的分辨率。然而，生物相容性 SWIR 造影剂的开发仍然具有挑战性。尽管最近取得了进展，但小分子 SWIR 荧光基团经常受到其显著疏水性的阻碍。我们报道了一个平台，该平台通过多功能荧光团中间体的后期官能团化生成一组用于 SWIR 成像的可溶性和功能性染料，从而在血清中提供具有明亮 SWIR 荧光的水溶性染料。具体来说，四磺酸盐衍生物只需 0.05 nmol 染料即可对脉管系统进行清晰的视频速率成像，而四铵染料显示出强大的细胞保留能力，可追踪肿瘤生长。此外，膦酸盐功能的掺入可实现清醒小鼠的骨骼成像。这种模块化设计为现有 SWIR 荧光基团的简单衍生化提供了见解，从而为体内生物成像引入了溶解度和生物活性 。