State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
Joint Laboratory of Opto-Functional Theranostics in Medicine and Chemistry, The First Hospital of Jilin University, Changchun, 130021, P. R. China.
Adv Sci (Weinh). 2022 Oct;9(30):e2203474. doi: 10.1002/advs.202203474. Epub 2022 Sep 1.
Carbon dots (CDs) or carbonized polymer dots (CPDs) are an emerging class of optical materials that have exceptional applications in optoelectronic devices, catalysis, detection, and bioimaging. Although cell studies of CPDs have produced impressive results, in vivo imaging requires available CPDs to fluoresce in the near-infrared-II (NIR-II) window (1000-1700 nm). Here, a two-step bottom-up strategy is developed to synthesize NIR-CPDs that provide bright emissions in both NIR-I and NIR-II transparent imaging windows. The designed strategy includes a hydrothermal reaction to form a stable carbon core with aldehyde groups, followed by the Knoevenagel reaction to tether the molecular emission centers. This procedure is labor-saving, cost-efficient, and produces a high yield. The NIR-CPDs enable high-performance NIR-II angiography and real-time imaging of the disease degree of colitis noninvasively. This technology may therefore provide a next-generation synthesis strategy for CPDs with rational molecular engineering that can accurately tune the absorption/emission properties of NIR-emissive CPDs.
碳点（CDs）或碳化聚合物点（CPDs）是一类新兴的光学材料，在光电设备、催化、检测和生物成像等领域有非常出色的应用。尽管关于 CPDs 的细胞研究已经取得了令人印象深刻的成果，但活体成像需要可在近红外二区（NIR-II）窗口（1000-1700nm）中荧光的 CPDs。在这里，开发了一种两步自上而下的策略来合成在 NIR-I 和 NIR-II 透明成像窗口都能提供明亮发射的 NIR-CPDs。所设计的策略包括水热反应以形成具有醛基的稳定碳核，然后进行 Knoevenagel 反应以连接分子发射中心。该过程省力、成本效益高，产率高。NIR-CPDs 能够实现高性能的 NIR-II 血管造影术和结肠炎疾病程度的实时无创成像。因此，该技术可能为 CPDs 提供一种具有合理分子工程的下一代合成策略，能够精确调整近红外发光 CPDs 的吸收/发射特性。
