Less Is More: Donor Engineering of a Stable Molecular Dye for Bioimaging in the NIR-IIb Window

作者：Tianbao Wang, Yufei Qin, Jinyu Wang, Yihan Xu, Jiaming Guo, Yiling Zhu, Huiyan Zhang, Yujie Qin, Zhongquan Qi, Hualong Fu, Ya‐Jun Liu, Mengchao Cui, Kaixiang Zhou · 发表于：Journal of Medicinal Chemistry · 年份：2025 · DOI：10.1021/acs.jmedchem.4c02866 · 被引用次数：15 · 研究领域：Nanoplatforms for cancer theranostics、Photoacoustic and Ultrasonic Imaging、Advanced Nanomaterials in Catalysis

Fluorescence molecular imaging aims to enhance clarity in the region of interest, particularly in the near-infrared IIb window (NIR-IIb, 1500–1700 nm). To achieve this, we developed a novel small-molecule dye, named DA-5, based on classic cyanine dyes (heptamethine or pentamethine is essential for wavelengths beyond 1000 nm). By reducing excessive polymethine to a single methine and disrupting symmetry to form an asymmetric donor-π-acceptor (D-π-A) architecture, we enhanced the donor’s electron-donating capability, yielding emission at 1088 nm. DA-5 exhibits superior properties, including excellent chemo- and photostability, resistance against solvatochromism-caused quenching, and antiaggregation in aqueous solution. With a large Stokes shift (241 nm) and high brightness (321 M –1 cm –1 ), DA-5 enables high-performance imaging of the lymphatic system, intestinal vessels, whole-body angiography, and cerebral and hindlimb microvasculature in NIR-IIb. This molecular design strategy offers a promising platform for advancing in vivo biophotonics.