Abstract：
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.
摘要：
荧光标记的DNA寡核苷酸和金纳米球已被频繁地用于生物传感器,提供有效的核酸检测。然而，金纳米球的有限负载能力破坏了整体灵敏度。在这项研究中,我们采用了四原子厚的超薄金纳米片(AuNSs)，利用“预混合模型”进行快速靶核酸检测。在这种方法中，荧光标记的DNA探针与靶核酸预孵育，然后加入AuNSs进行探针吸附和荧光猝灭。通过开发的方法，我们在30min内高效、快速地检测出SARS-CoV-2N基因序列,涉及短暂的15分钟靶标预孵育和随后的15分钟游离探针吸附以及AuNSs的荧光猝灭。与金纳米球相比，这种方法表现出更高的灵敏度，检测限(LOD)为0.808nM。此外，在模拟生物样品中获得了异常的回收率。该研究介绍了一种以快速为特征的核酸传感有效策略，灵敏度提高,操作方便,和鲁棒性。这些发现鼓励了采用2D纳米材料的快速生物标志物传感方法的进一步发展。
