The two-photon absorption properties of a pyrene-pyridinium dye (1) were studied for potential application in two-photon spectroscopy. When probe 1 was used in cellular two-photon fluorescence microscopy imaging, it allowed the visualization of nuclei in live cells with a relatively low probe concentration (such as 1 μM). Spectroscopic evidence further revealed that probe 1 interacted with DNA as an intercalator. The proposed DNA intercalation properties of probe 1 were consistent with the experimental findings that suggested that the observed nucleus staining ability is dependent on the substituents on the pyridinium fragment of the probe.

中文翻译：

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一种基于pyr的双光子可激发荧光探针，用于可视化活细胞中的细胞核。

研究了-吡啶染料（1）的双光子吸收特性，有望在双光子光谱中应用。当探针1用于细胞双光子荧光显微镜成像时，它可以使探针浓度相对较低（例如1μM）的活细胞中的细胞核可视化。光谱学证据进一步表明，探针1作为嵌入剂与DNA相互作用。探针1的拟议DNA嵌入特性与实验结果一致，该实验结果表明观察到的核染色能力取决于探针的吡啶鎓片段上的取代基。