H2S-activatable near-infrared afterglow luminescent probes for sensitive molecular imaging in vivo

Afterglow luminescent probes with high signal-to-background ratio show promise for in vivo imaging; however, such probes that can be selectively delivered into target sites and switch on afterglow luminescence remain limited. We optimize an organic electrochromic material and integrate it into near-infrared (NIR) photosensitizer (silicon 2,3-naphthalocyanine bis( trihexylsilyloxide) and (poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]) containing nanoparticles, developing an H2S-activatable NIR afterglow probe (F1(2+)-ANP). F1(2+)-ANP displays a fast reaction rate (1563 +/- 141M(-1) s(-1)) and large afterglow turn-on ratio (similar to 122-fold) toward H2S, enabling high-sensitivity and -specificity measurement of H2S concentration in bloods from healthy persons, hepatic or colorectal cancer patients. We further construct a hepatic-tumor- targeting and H(2)Sactivatable afterglow probe (F1(2+)-ANP-Gal) for noninvasive, real-time imaging of tiny subcutaneous HepG(2) tumors (<3 mm in diameter) and orthotopic liver tumors in mice. Strikingly, F1(2+)-ANP- Gal accurately delineates tumor margins in excised hepatic cancer specimens, which may facilitate intraoperative guidance of hepatic cancer surgery.