Linker Engineering toward NIR-II Metal-Organic Framework with Maximal Emission beyond 1000 nm for Inflammatory Bowel Disease Imaging.

Herein, by integrating benzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) with strong electron-withdrawing capacity and 4,4'-azanediyldibenzoic acid with strong electron-donating capacity into one donor-acceptor-donor type organic linker, a near-infrared-II (NIR-II) emissive zirconium-tetracarboxylate framework, HIAM-4030, was reported. HIAM-4030 possesses an ftw topology and shows a maximum emission peak at 1052 nm. The HIAM-4030-based nanocomposite exhibits targeted delivery, anti-inflammatory efficacy, and real-time, noninvasive visualization of inflammatory bowel disease via NIR-II fluorescence imaging. This work sheds light on the rational design and construction of luminescent metal-organic frameworks with NIR-II emission behaviors for biomedical applications.