Nitric oxide (NO) is a messenger molecule in organisms, participating in the regulation of many biological processes. The abnormal expression of NO is often observed in a variety of diseases, including cerebral ischemia, atherosclerosis, and cancer. However, a suitable tool that can directly and sensitively detect NO in vitro and in vivo is important for understanding its various biological functions. In this report, a new fluorescent probe for nitric oxide, DHP-4, was prepared, based on dihydropyridine-coumarin. DHP-4 was able to greatly enhance the fluorescence of NO, but did not affect the fluorescence emissions of other reactive oxygen species and nitrogen species, demonstrating its highly selective and sensitive response to NO. The probe generated stable optical signals in a buffer solution at pH values ranging from 3 to 10. In addition, DHP-4 could detect NO directly, showed low cellular toxicity, and was successfully applied to determine NO in Raw 264.7 cells, indicating its great potential as a tool for investigating the biological roles of NO in vivo.

中文翻译：

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基于二氢吡啶-香豆素的荧光探针，用于对活细胞中的一氧化氮进行成像。

一氧化氮（NO）是生物体中的信使分子，参与许多生物过程的调节。通常在多种疾病中观察到NO的异常表达，包括脑缺血，动脉粥样硬化和癌症。但是，对于了解其各种生物学功能而言，可以在体外和体内直接和灵敏地检测NO的合适工具很重要。在本报告中，基于二氢吡啶-香豆素制备了一种新的一氧化氮荧光探针DHP-4。DHP-4能够大大增强NO的荧光，但不影响其他活性氧和氮的荧光发射，证明了其对NO的高度选择性和敏感性。该探针在pH值为3到10的缓冲溶液中产生稳定的光信号。此外，DHP-4可以直接检测NO，显示低细胞毒性，并成功应用于生Raw 264.7细胞中NO的测定，表明它的优势作为研究NO在体内生物学作用的工具的潜力。