The long-wavelength region of the near-infrared-IIb (NIR-IIb, 1,500–1,700 nm) imaging window has become an ideal window for in vivo imaging due to the suppressed photon scattering and near-zero autofluorescence of biological tissues. Therefore, it is necessary to develop fluorescent probes with excellent fluorescence performance and stability for NIR-IIb fluorescence imaging. In this work, zinc-doped silver telluride quantum dots (Zn:Ag₂Te QDs) with bright fluorescence in the NIR-IIb window were synthesized. The introduction of Zn dopants inhibited crystal defects and reduced non-radiative transitions. Therefore, the quantum yield and fluorescence lifetime of Zn:Ag₂Te QDs were significantly improved. In addition, Zn-doping increased the number of ligands on the surface of QDs, thus enhancing the colloidal stability of Zn:Ag₂Te QDs. Moreover, the PEGylated Zn:Ag₂Te QDs with high absolute quantum yield realized noninvasive imaging of cerebral vascular of mouse with high resolution able to distinguish blood capillary, which could be utilized to monitor the brain condition of mice after traumatic brain injury.

由于抑制了光子散射和生物组织的近零自发荧光，近红外-IIb（NIR-IIb，1,500–1,700 nm）成像窗口的长波长区域已成为体内成像的理想窗口。因此，有必要开发具有优异荧光性能和稳定性的荧光探针用于NIR-IIb荧光成像。在这项工作中，合成了在 NIR-IIb 窗口中具有明亮荧光的锌掺杂碲化银量子点 (Zn:Ag ₂ Te QDs)。Zn 掺杂剂的引入抑制了晶体缺陷并减少了非辐射跃迁。因此，Zn:Ag _{2的量子产率和荧光寿命}Te QD 得到了显着改善。此外，Zn掺杂增加了QDs表面的配体数量，从而提高了Zn:Ag ₂ Te QDs的胶体稳定性。此外，具有高绝对量子产率的聚乙二醇化Zn:Ag ₂ Te QDs实现了小鼠脑血管的无创成像，高分辨率能够区分毛细血管，可用于监测外伤性脑损伤后小鼠的脑状况。