Fluorescently labeled DNA oligonucleotides and gold nanospheres have been frequently utilized in biosensors, providing efficient nucleic acid detection. Nevertheless, the restricted loading capacity of gold nanospheres undermines overall sensitivity. In this study, we employed four-atom-thick ultrathin gold nanosheets (AuNSs), utilizing a “pre-mix model” for rapid target nucleic acid detection. In this approach, fluorescently labeled DNA probes were pre-incubated with the target nucleic acid, followed by the addition of AuNSs for probe adsorption and fluorescence quenching. With the developed method, we efficiently and rapidly detected the SARS-CoV-2 N gene sequence within 30 min, involving a brief 15-min target pre-incubation and a subsequent 15-min adsorption of free probes and fluorescence quenching by AuNSs. This method exhibited heightened sensitivity compared to gold nanospheres, boasting a limit of detection (LOD) of 0.808 nM. Furthermore, exceptional recovery was achieved in simulated biological samples. The study introduces an effective strategy for nucleic acid sensing characterized by rapidity, heightened sensitivity, ease of operation, and robustness. These findings encourage further development of rapid biomarker sensing methods employing 2D nanomaterials.

中文翻译：

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使用超薄金纳米片进行快速荧光核酸传感


荧光标记的 DNA 寡核苷酸和金纳米球经常用于生物传感器，提供有效的核酸检测。然而，金纳米球有限的负载能力损害了整体灵敏度。在这项研究中，我们采用了四个原子厚的超薄金纳米片（AuNS），利用“预混合模型”进行快速目标核酸检测。在这种方法中，荧光标记的 DNA 探针与目标核酸预孵育，然后添加 AuNS 进行探针吸附和荧光猝灭。利用所开发的方法，我们在 30 分钟内高效快速地检测到 SARS-CoV-2 N 基因序列，包括短暂的 15 分钟目标预孵育以及随后 15 分钟的游离探针吸附和 AuNS 荧光猝灭。与金纳米球相比，该方法表现出更高的灵敏度，检测限 (LOD) 为 0.808 nM。此外，在模拟生物样品中实现了出色的回收率。该研究引入了一种有效的核酸传感策略，其特点是快速、灵敏度高、易于操作和稳健。这些发现鼓励进一步开发利用二维纳米材料的快速生物标志物传感方法。