An activatable probe able to detect RONS level underlying the development of rheumatoid arthritis (RA) would be far-reaching for the diagnosis and drug efficacy assessment of RA. Despite more and more evidence suggests that ONOO⁻ is an important signaling molecule participating in the RA disease, only rare fluorescent probes can detect ONOO⁻ in this disease with satisfying performance. To this end, we designed and synthesized a novel activatable AIE fluorescent probe (DPPO-PN) for the detection of ONOO⁻ levels in RA. The probe linearly responds to 0–10 μM ONOO⁻ with a significant far-red fluorescence enhancement at 632 nm in 30 s (F/F₀ = 161-fold, LOD = 10 nM) upon the excitation of 490 nm, elucidating excellent sensing abilities for ONOO⁻ in cuvettes. Moreover, the fluctuations of intracellular ONOO⁻ levels caused by adscititious adding or stimulant provoking could be real-time captured and visualized with this probe by confocal imaging. Further, the intravital imaging of ONOO⁻ in LPS-induced and CFA-induced RA mouse models also can be achieved with the aid of the probe, substantiating the burst of ONOO⁻ in the RA process. Therefore, this work not only offers an auxiliary tool for the diagnosis of RA but also would benefit our understanding of the ONOO⁻‘s roles in RA.

能够检测类风湿性关节炎 (RA) 发展的 RONS 水平的可激活探针对于 RA 的诊断和药物疗效评估具有深远的意义。尽管越来越多的证据表明 ONOO ^-是参与 RA 疾病的重要信号分子，但只有罕见的荧光探针才能检测到这种疾病中的 ONOO ^-并具有令人满意的性能。为此，我们设计并合成了一种新型可激活 AIE 荧光探针 ( DPPO-PN)，用于检测 RA 中的 ONOO ^-水平。该探针线性响应 0–10 μM ONOO ^-在 30 秒内在 632 nm 处具有显着的远红外荧光增强 ( F/F ₀ = 161 倍，LOD = 10 nM) 在 490 nm 的激发下，阐明了 ONOO ⁻在比色皿中的出色传感能力。此外，细胞内 ONOO ^-由外加添加或兴奋剂激发引起的水平波动可以通过共聚焦成像用该探针实时捕获和可视化。此外，ONOO ^-在 LPS 诱导和 CFA 诱导的 RA 小鼠模型中的活体成像也可以借助探针实现，证实 ONOO ^-在 RA 过程中的爆发。因此，这项工作不仅为 RA 的诊断提供了一个辅助工具，而且有助于我们理解 ONOO ^-在 RA 中的作用。