Precise In Vivo Inflammation Imaging Using In Situ Responsive Cross‐linking of Glutathione‐Modified Ultra‐Small NIR‐II Lanthanide Nanoparticles

To improve the bioimaging signal-to-noise ratio (SNR), long-term imaging capability, and decrease the potential biotoxicity, an in vivo cross-linking strategy was developed by using sub-10 nm, glutathione-modified, lanthanide nanoprobes. After administration, the nanoprobes cross-link in response to reactive oxygen species (ROS) at the inflamed area and enable the quick imaging of ROS in the second near-infrared (NIR-II) window. These nanoprobes could be rapidly excreted due to their ultra-small size. This strategy may also be applied to other ultra-small contrast agents for the precise bioimaging by in situ lesion cross-linking.