The detection and stabilization of G-quadruplexes (G4s) in living systems is of enormous applicability in the fields of chemical biology and therapeutic materials. Whereas DNA serves as a genetic material, RNA functions in the regulation and expression of genetic materials. Even there is various report on fluorescent probes invitro G4s recognitions, in this review we highlighted briefly, in-cellulo identification of G4s along with conventional methods principles. Although there are varieties of G4-forming sequences in the genome, targeting a specific type (topology) in living cells is highly challenging because of the high instability of G4s in cellular/subcellular systems. In contrast, several reports describe the in vitro identification of G4s, along with in-cell demonstrations, using efficient fluorescent probes, through either intrinsic or extrinsic approaches. In the intrinsic mode, the sensing results from the use of highly selective synthetic fluorescent oligonucleotides or proteins (a labeling approach). In the extrinsic mode, quencher-free small molecular probes are used to recognize specific G4s under physiological conditions. Because of their robustness, simplicity, and ease of handling, this review describes recent trends in the use of blue/green, green, red, and near-infrared (NIR) fluorescent probes for the recognition of G4s in live cells-and, particularly, those approaches employing quencher-free probes. Also highlighted are a few labeled probes, and their in cellulo localizations, which were accomplished upon the formation of non-canonical G4s under specified conditions and supplemented by exogenous G4-forming components, without harnessing cellular physiological conditions.

在生物系统中检测和稳定G-四链体（G4）在化学生物学和治疗材料领域具有巨大的适用性。DNA是遗传物质，而RNA在遗传物质的调控和表达中起作用。甚至还有关于荧光探针体外G4s识别的各种报道，在这篇综述中，我们简要介绍了G4s的细胞内鉴定以及常规方法原理。尽管基因组中存在多种形成G4的序列，但由于细胞/亚细胞系统中G4的高度不稳定性，在活细胞中靶向特定类型（拓扑）仍具有很高的挑战性。相比之下，一些报告描述了体外通过有效的荧光探针通过内在或外在方法鉴定G4并进行细胞内演示。在固有模式下，感应是由于使用高度选择性的合成荧光寡核苷酸或蛋白质（标记方法）而产生的。在外部模式下，无淬灭剂的小分子探针用于识别生理条件下的特定G4。由于它们的坚固性，简单性和易于操作性，本综述描述了使用蓝色/绿色，绿色，红色和近红外（NIR）荧光探针识别活细胞中G4的最新趋势-特别是，那些采用无淬灭探针的方法。还突出显示了一些标记的探针，以及它们在纤维素中的含量。 本地化，这是在指定条件下形成非经典G4时完成的，并辅以外源性G4形成成分，而无需利用细胞生理条件。