Fluorescent probes for nitric oxide (NO), or more frequently for its oxidized surrogate dinitrogen trioxide (N₂O₃), have enabled scientists to study the contributions of this signaling molecule to many physiological processes. Seeking to improve upon limitations of other probes, we have developed a family of fluorescent probes based on a 2-amino-3′-dialkylaminobiphenyl core. This core condenses with N₂O₃ to form benzo[c]cinnoline structures, incorporating the analyte into the newly formed fluorophore, which results in product fluorescence with virtually no background contribution from the initial probe. We varied the substituents in the core in order to optimize both the reactivity of the probes with N₂O₃ and their cinnoline products' fluorescence wavelengths and brightness. The top candidates were then applied to cultured cells to verify that they could respond to NO within cellular milieus, and the top performer, NO₅₃₀, was compared with a “gold standard” commercial probe, DAF-FM, in a macrophage-derived cell line, RAW 264.7, stimulated to produce NO. NO₅₃₀ demonstrated similar or better sensitivity and higher selectivity for NO than DAF, making it an attractive potential alternative for NO tracking in various applications.

中文翻译：

---

一氧化氮替代N2O3的基于2-氨基-3'-二烷基氨基联苯的荧光细胞内探针

一氧化氮（NO）或更常见的三氧化二氮（N ₂ O ₃）荧光探针使科学家们能够研究这种信号分子在许多生理过程中的作用。为了改善其他探针的局限性，我们开发了基于2-氨基-3'-二烷基氨基联苯核心的荧光探针家族。该核与N ₂ O ₃缩合形成苯并[ c ]喹啉结构，将分析物掺入新形成的荧光团中，这导致产物荧光几乎没有初始探针的背景贡献。我们改变了核心中的取代基，以优化探针与N的反应性₂ O ₃及其cinnoline产物的荧光波长和亮度。然后将排名靠前的候选基因应用于培养的细胞，以验证它们是否可以对细胞环境中的NO作出反应，并将性能最高的NO ₅₃₀与“金标准”商业探针DAF-FM在巨噬细胞衍生的细胞中进行比较线，RAW 264.7，刺激产生NO。与DAF相比，NO ₅₃₀对NO表现出相似或更好的灵敏度和更高的选择性，使其成为各种应用中NO追踪的诱人的潜在替代品。