An activatable Near-Infrared afterglow luminescent nanoprobe with ultralong Half-Life for in vivo H2S imaging

• Hydrogen sulfide-activatable NIR afterglow nanoprobe (L-T NPs) was developed. • L-T NPs exhibit an ultralong half-life (t 1/2 = 2.7 h). • This nanoprobe was applied for afterglow imaging in various mice models. Accurate detection of hydrogen sulfide (H 2 S) is critical for preventing and assessing the progression of H 2 S-realted diseases; however, it remains a formidable challenge due to the transient and dynamic nature of H 2 S. Herein, we present a novel H 2 S-activatable near-infrared (NIR) afterglow luminescent nanoprobe (L-T NPs) by encapsulating H 2 S-responsive afterglow luminophore (LAL) and NIR emissive aggregation-induced emission (AIE) photosensitizer (TTMN) into nanoparticles. L-T NPs exhibit an ultralong half-life (t 1/2 = 2.7 h), which is the longest among all known H 2 S-activatable afterglow probes. In the presence of H 2 S, L-T NPs emit NIR afterglow signal with high signal-to-background ratio, good sensitivity, and selectivity through effective chemiluminescence resonance energy transfer (CRET) process. This nanoprobe not only accurately discriminates between inflammation and normal tissue, but also monitors the changes of H 2 S levels in acetaminophen (APAP)-induced hepatotoxicity mice model using afterglow imaging. This work provides a promising tool to investigate and comprehend the role of H 2 S in the biomedical field.