Hydrogen peroxide (H₂O₂) is a small molecule of reactive oxygen species, mainly produced by cell mitochondria, which plays an important role in physiological processes. Excess of H₂O₂ in normal cells could causes a variety of diseases. For that reason, it is very significant to emerge a detection method with high-precision for H₂O₂. Herein, we reported a structurally novel fluorescent probe, para-nitrophenyl oxoacetyl rhodamine (RhB-NIR) for the detection of H₂O₂ levels in living cells. The results show that the Stokes shift for RhB-NIR is 140 nm, much larger than those for other reported rodamine derivatives. RhB-NIR shows satisfactory specificity and high sensitivity for the detection of H₂O₂. Excellent linear relationship with H₂O₂ within a certain concentration range (0 - 10 μM) was displayed, and the limit of detection (LOD) is 61 nM. More importantly, RhB-NIR realized fluorescence imaging of H₂O₂ in living cells. In addition, RhB-NIR also shows great potential for targeting mitochondria in cell colocalization experiments, in which the Pearson's coefficient is 0.91 using Rhodamine 123 as a reference. This probe will be a promising tool for detecting H₂O₂ in the future research.

过氧化氢（H ₂ O ₂）是一种活性氧的小分子，主要由细胞线粒体产生，在生理过程中起着重要作用。正常细胞中过量的H ₂ O ₂可能引起多种疾病。因此，提出一种高精度的H ₂ O ₂检测方法非常重要。在这里，我们报道了一种结构新颖的荧光探针，对硝基苯基氧乙酰基罗丹明（RhB-NIR），用于检测活细胞中的H ₂ O ₂水平。结果表明，RhB-NIR的斯托克斯位移波长为140 nm，比其他报道的罗丹明衍生物大得多。RhB-NIR对H ₂ O ₂的检测显示出令人满意的特异性和高灵敏度。在一定浓度范围（0-10μM）中，与H ₂ O _2的线性关系良好，检出限（LOD）为61 nM。更重要的是，RhB-NIR实现了活细胞中H ₂ O _2的荧光成像。此外，RhB-NIR还显示了在细胞共定位实验中靶向线粒体的巨大潜力，其中以罗丹明123为参考的皮尔逊系数为0.91。该探针将成为未来研究中检测H ₂ O ₂的有前途的工具。