An Activatable Afterglow/MRI Bimodal Nanoprobe with Fast Response to H2S for In Vivo Imaging of Acute Hepatitis.

Accurate detection of hepatic hydrogen sulfide (H 2 S) to monitor H 2 S-related enzymes' activity is critical for acute hepatitis diagnosis, but remains a challenge due to the dynamic and transient nature of H 2 S. Here, we report a H 2 S-activatable near-infrared afterglow/MRI bimodal probe F1 -GdNP, which shows an "always-on" MRI signal and "off-on" afterglow signal toward H 2 S. F1 -GdNP shows fast response, high sensitivity and specificity toward H 2 S, permitting afterglow imaging of H 2 S and evaluation of cystathionine γ -lyase's activity in living mice. We further employ the high spatial-resolution MRI signal of F1 -GdNP to track its delivery and accumulation in liver. Importantly, F1 -GdNP offers a high signal-to-background ratio (SBR = 86.2 ± 12.0) to sensitively report on the increased hepatic H 2 S level in the acute hepatitis mice via afterglow imaging, which correlated well with the upregulated CSE activity in the liver, showcasing the good potential of F1 -GdNP for monitoring of acute hepatitis process in vivo.