近红外二区（1 000～1 700 nm）活体光学成像除了具有一般光学成像技术灵敏度高、非侵入性、实时成像等优点，更因其自体生物荧光背景低、组织穿透度深、成像清晰等诸多优势而被视为目前在临床应用中较有前景的一种光学成像技术。在近红外二区成像体系中，近红外二区荧光探针是关键的技术难点，也是当下的研究热点。其中，因纳米材料具有独特的物理及化学性能，近红外二区荧光纳米探针成为目前近红外二区光学成像技术的理想造影剂。目前已报道的可作为近红外二区荧光纳米探针的无机材料包括量子点、稀土纳米粒子、单壁碳纳米管，已报道的有机材料主要是共轭聚合物。该文综述上述近红外二区荧光纳米探针的研究进展，以期更好地了解其在生物医学领域的应用，并推进近红外二区活体成像在生物医学领域的研究及临床应用。

Besides the advantages of high sensitivity, non-invasive, and real-time imaging that the general optical imaging technologies have, the second near-infrared (1 000–1 700 nm) in vivo imaging is regarded as one of the most promising optical imaging technologies in clinical application at present due to its advantages such as low autofluorescence background, deep tissue penetration and clear imaging. In the second near-infrared imaging system, the fluorescence probe is the most critical technical difficulty and the current research hotspot. Thereinto, due to the unique physical and chemical properties of nanomaterials, the second near-infrared fluorescent nanoprobe is an ideal contrast agent for the current second near-infrared optical imaging technology. The reported inorganic materials that can be used as the second near-infrared fluorescent nanoprobes include quantum dots, rare earth nanoparticles, and single-walled carbon nanotubes, and the reported organic materials are mainly conjugated polymers. In this paper, the research progresses of the second near-infrared fluorescence nanoprobes mentioned above are reviewed into better understand their application to the field of biomedicine, and promote the further research and clinical application of the second near-infrared in vivo imaging to the biomedical field.