Sentinel lymph node (SLN) imaging is vital for tumor staging and treatment decision-making, and current methods for SLN imaging suffer from a short retention time, poor penetration depth, and low signal-to-noise ratio. As a cutting-edge technology, second near-infrared wavelength region (NIR-II) aggregation-induced emission (AIE) luminogens (AIEgens) are promising for circumventing these challenges; however, construction of such molecules with ultralong absorption wavelengths remains a significant challenge. Here we conducted molecular engineering, constructing a NIR-II AIEgen (NIR-920) with the longest maximum absorption wavelength. NIR-920 nanoparticles (NPs) presented bright fluorescence and achieved high-performance imaging of lymph nodes in the NIR-II/NIR-IIb window. Compared with the clinically used indocyanine green (ICG), NIR-920 nanoparticles have many superior advantages, including retention time, penetration depth, signal-to-noise ratio, and photostability. Utilization of NIR-920 NPs allowed fast and accurate surgical navigation of SLNs. This work provides useful insight into designing extraordinarily prominent molecular probes for high-quality lymph node imaging and surgical navigation.

前哨淋巴结 (SLN) 成像对于肿瘤分期和治疗决策至关重要，而当前的 SLN 成像方法存在保留时间短、穿透深度差和信噪比低的问题。作为一项尖端技术，第二近红外波长区域 (NIR-II) 聚集诱导发射 (AIE) 发光体 (AIEgens) 有望解决这些挑战；然而，构建具有超长吸收波长的此类分子仍然是一项重大挑战。在这里，我们进行了分子工程，构建了具有最长最大吸收波长的 NIR-II AIEgen (NIR-920)。NIR-920 纳米粒子 (NPs) 呈现出明亮的荧光，并在 NIR-II/NIR-IIb 窗口中实现了淋巴结的高性能成像。与临床使用的吲哚菁绿（ICG）相比，NIR-920 纳米粒子具有许多优越的优势，包括保留时间、穿透深度、信噪比和光稳定性。利用 NIR-920 NPs 可以快速准确地对 SLN 进行手术导航。这项工作为设计用于高质量淋巴结成像和手术导航的非凡分子探针提供了有用的见解。