Nitric oxide (NO) is an important effector molecule in host defence against bacterial pathogens. The development of fluorescence imaging to monitor NO production in vitro and in vivo will increase our understanding of its biological role. Recently, a novel ‘trappable’ fluorescent blue ‘turn-on’ Cu(II)-complexed coumarin-based probe (CB) has been developed to detect NO. In this study, CB was investigated to evaluate its ability to detect NO in macrophages. Using confocal microscopy, NO was successfully detected in macrophages in the presence of stimuli that induce nitric oxide synthase (iNOS), the enzyme responsible for production of NO. The time dependence and subcellular compartmentalisation of CB in macrophages were evaluated. The probe can be trapped within cells and reacts directly and specifically with NO, rendering it a promising tool for imaging NO in response to pharmacological agents that modulate its level, for example during bacterial infections.

一氧化氮（NO）是宿主防御细菌病原体的重要效应分子。荧光成像的发展并监控NO产生体外和体内将会增加我们对其生物学作用的了解。最近，已经开发出一种新型的“可诱捕的”荧光蓝“开启” Cu（II）复合香豆素基探针（CB）来检测NO。在这项研究中，对CB进行了研究，以评估其检测巨噬细胞中NO的能力。使用共聚焦显微镜，在存在诱导一氧化氮合酶（iNOS）的刺激物的刺激下，巨噬细胞中成功检测到NO。评估了时间依赖性和巨噬细胞中CB的亚细胞区室化。该探针可以捕获在细胞内，并直接与NO发生特异性反应，从而使其成为一种有前景的工具，可以对NO进行成像，以响应调节其水平的药理剂，例如在细菌感染期间。