Endogenous HS-Triggered In Situ Synthesis of NIR-II-Emitting Nanoprobe for In Vivo Intelligently Lighting Up Colorectal Cancer.

Overexpression of endogenous HS is one of the key characteristic in colon cancer. However, developing endogenous HS-activated optical probes for specific diagnosis of colorectal cancer is rarely explored. Herein, an in situ HS-activatable second near-infrared (NIR-II)-emitting nanoprobe based on Ag-chicken egg white (Ag-CEW) complex for intelligently lighting up colorectal cancer was explored. The designed Ag-CEW complex holds efficient NIR-II emission of 1,000-1,400 nm via endogenous HS-induced in situ chemical reaction to form AgS quantum dots (QDs). After reaction, the designed Ag-CEW complex with high photo-stability and biocompatibility was successfully used for NIR-II imaging-guided specific visualization and precise location of colorectal cancer via endogenous HS activation. Therefore, our findings provide a new route for specifically targeting diagnosis of colon cancer based on the in situ-activatable NIR-II probe.