Liu Yongchao, Teng Lili, Zhang Bo, Zhang Xiao-Bing, Song Guosheng
State Key Laboratory of New Pharmaceutical Preparations and Excipients, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, College of Chemistry and Materials Science, Hebei University Baoding 071002 China
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University Changsha 410082 China
Chem Sci. 2025 Jun 24. doi: 10.1039/d5sc02705e.
Ratiometric fluorescent probes in the second near-infrared window (NIR-II) with a self-calibration function are sought after for reliable imaging of physiological and pathological processes. Nevertheless, current ratiometric NIR-II fluorescent probes usually show severe spectral overlap in the emission channel, resulting in inevitable sacrifice of the emission intensity of the probe and compromised imaging quality in the NIR-II region. To address these challenges, we developed a novel dual-excitation ratiometric NIR-II fluorescence nanoplatform (DERF-NP), in which the intensity ratio of the same full-wavelength emission from 1000 to 1700 nm under two non-overlapping monochrome excitations with distinct responses is conventionally defined as the quantification parameter. As a proof of concept, DERF-NO, our test case of a ratiometric NIR-II nanoprobe for NO imaging with high sensitivity and quality, was developed based on an energy transfer strategy, which showed increased emission with excitation at 660 nm and constant emission with excitation at 808 nm upon activation of NO. ratiometric NIR-II fluorescence imaging with DERF-NO successfully tracked macrophage polarization and lymphatic metastasis, suggesting the extensive distribution and critical role of macrophages in tumorigenesis and progression. This dual-excitation ratiometric imaging strategy may provide a novel approach for designing ratiometric NIR-II fluorescent probes and has great application potential for intravital imaging analysis.
具有自校准功能的第二近红外窗口（NIR-II）比率荧光探针在生理和病理过程的可靠成像中备受青睐。然而，目前的比率NIR-II荧光探针在发射通道中通常表现出严重的光谱重叠，导致探针发射强度不可避免地牺牲，以及NIR-II区域成像质量受损。为应对这些挑战，我们开发了一种新型双激发比率NIR-II荧光纳米平台（DERF-NP），其中在两种具有不同响应的非重叠单色激发下，1000至1700 nm相同全波长发射的强度比通常被定义为量化参数。作为概念验证，基于能量转移策略开发了DERF-NO，这是我们用于NO成像的高灵敏度和高质量比率NIR-II纳米探针的测试案例，在NO激活后，其在660 nm激发下发射增加，在808 nm激发下发射恒定。使用DERF-NO进行的比率NIR-II荧光成像成功跟踪了巨噬细胞极化和淋巴转移，表明巨噬细胞在肿瘤发生和进展中广泛分布且起关键作用。这种双激发比率成像策略可能为设计比率NIR-II荧光探针提供一种新方法，并在活体成像分析中具有巨大的应用潜力。
