The accurate and sensitive in situ imaging of inflammatory bowel disease (IBD) is critical for the precise diagnosis and treatment of this disease, but it remains a challenge for fluorescent probes because of a more dynamical shift of pH in the intestinal tract than under other physical conditions. To address this issue, we report here that the rational introduction of the ortho-halogen bond at the electron acceptor can regulate the protonation and deprotonation of fluorescent dye, resulting in a pH-insensitive dye (pH 5–12). Therefore, constructing a near-infrared (NIR) probe, 2F-RBH, which effectively avoids this pH effect with a stable fluorescent signal and selectively indicates sites of inflammation in situ, by tracking peroxynitrite (ONOO⁻) in an acute colitis mouse model. Collectively, our results highlight that 2F-RBH is a promising probe for the imaging of IBD and that our pH-insensitive dye has potentially desirable properties for in vivo bioimaging.

炎症性肠病 (IBD) 的准确和灵敏的原位成像对于这种疾病的精确诊断和治疗至关重要，但它仍然是荧光探针的挑战，因为肠道 pH 值的动态变化比其他物理条件下更大状况。为了解决这个问题，我们在此报告，在电子受体处合理引入邻卤素键可以调节荧光染料的质子化和去质子化，从而产生 pH 不敏感染料 (pH 5–12)。因此，构建近红外 (NIR) 探针2F-RBH可有效避免这种具有稳定荧光信号的 pH 效应，并选择性地原位指示炎症部位，通过在急性结肠炎小鼠模型中追踪过氧亚硝酸盐 (ONOO ^{- )。}总的来说，我们的结果强调2F-RBH是一种很有前途的 IBD 成像探针，并且我们的 pH 不敏感染料具有体内生物成像的潜在理想特性。