Owing to reduced light scattering and tissue autofluorescence, in vivo fluorescence imaging in the 1,000–3,000-nm near-infrared II (NIR-II) spectral range can afford non-invasive imaging at depths of millimetres within biological tissue. Infrared fluorescent probes labelled with antibodies or other targeting ligands also enable NIR-II molecular imaging at the single-cell level. Here we present recent developments in the design of fluorophores and probes emitting in the NIR-II window based on organic synthesis and nanoscience approaches. We also review advances in NIR-II wide-field and microscopy imaging modalities, with a focus on preclinical imaging and promising clinical translation case studies. Finally, we outline current issues and challenges for the wider adoption of NIR-II imaging in biomedical research and clinical imaging.

由于光散射和组织自发荧光减少，1,000–3,000 nm 近红外 II (NIR-II) 光谱范围内的体内荧光成像可以在生物组织内毫米深度进行非侵入性成像。用抗体或其他靶向配体标记的红外荧光探针还可以在单​​细胞水平上进行 NIR-II 分子成像。在这里，我们介绍基于有机合成和纳米科学方法的 NIR-II 窗口中发射的荧光团和探针设计的最新进展。我们还回顾了 NIR-II 广域和显微镜成像模式的进展，重点关注临床前成像和有前景的临床转化案例研究。最后，我们概述了在生物医学研究和临床成像中更广泛采用 NIR-II 成像的当前问题和挑战。