An endogenous H₂S-triggered intelligent optical nanoprobe combining second near-infrared (NIR-II) fluorescence with photoacoustic (PA) imaging can provide more comprehensive information to further improve the sensitivity and reliability of diagnosis for colorectal tumor, which is rarely explored. Herein, an endogenous H₂S-triggered SiO₂@Ag nanoprobe was designed for in situ dual-modal NIR-II/PA imaging of colorectal cancer. The designed dual-modal nanoprobe can be converted to SiO₂@Ag₂S after in situ biosynthesis via a sulfuration reaction with the over-expressed endogenous H₂S in the colorectal tumor. More importantly, the designed SiO₂@Ag nanoprobe exhibits high sensitivity and specificity for diagnosing colorectal cancer in vivo via dual-modal NIR-II/PA imaging. These results provide a new NIR-II/PA dual-modal imaging strategy for noninvasive intelligent detection of colorectal cancer.

中文翻译：

---

用于大肠癌高特异性成像的 H2S 触发双模第二近红外/光声智能纳米探针

结合第二近红外（NIR-II）荧光和光声（PA）成像的内源性H ₂ S触发智能光学纳米探针可以提供更全面的信息，以进一步提高对结直肠肿瘤诊断的敏感性和可靠性，这在目前很少被探索。在此，设计了一种内源性 H ₂ S 触发的 SiO ₂ @Ag 纳米探针，用于结直肠癌的原位双模 NIR-II/PA 成像。在原位生物合成后，设计的双模式纳米探针可以通过与过表达的内源性 H ₂的硫化反应转化为 SiO ₂ @Ag ₂ SS 在结直肠肿瘤中。更重要的是，设计的 SiO ₂ @Ag 纳米探针通过双模态 NIR-II/PA 成像在体内诊断结直肠癌方面表现出高灵敏度和特异性。这些结果为大肠癌的无创智能检测提供了一种新的NIR-II/PA双模态成像策略。