Abstract：
Since the outbreak of the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) at the end of 2019, the spread of the virus has posed a significant threat to public health and the global economy. This work proposed a one-step, dual-structure-switching aptamer-mediated signal amplification cascade for rapid and sensitive detection of the SARS-CoV-2 nucleocapsid protein. This system consisted of two DNA aptamers with structure-switching functionality and fuel DNA, where a cascade of strand hybridization and displacement triggered fluorescence generation and signal amplification. This aptamer-based amplification cascade required neither an amplification stage using enzymes nor pre-processing steps such as washing, viral isolation, and gene extraction. The assay could distinguish SARS-CoV-2 from other respiratory viruses and detect up to 1.0 PFU/assay of SARS-CoV-2 within 30 min at room temperature. In 35 nasopharyngeal clinical samples, the assay accurately assessed 25 positive and 10 negative clinical swab samples, which were confirmed using quantitative polymerase chain reaction. The strategy reported herein can help detect newly emerging pathogens and biomarkers of various diseases in liquid samples. In addition, the developed detection system consisting of only DNA and fluorophores can be widely integrated into liquid biopsy platforms for disease diagnosis.
摘要：
自2019年底新型严重急性呼吸道综合征冠状病毒-2（SARS-CoV-2）爆发以来，该病毒的传播对公共卫生和全球经济构成了重大威胁。这项工作提出了一个步骤，双结构转换适体介导的信号放大级联，用于快速和灵敏地检测SARS-CoV-2核衣壳蛋白。该系统由两个具有结构转换功能的DNA适体和燃料DNA组成，其中链杂交和置换的级联触发了荧光产生和信号放大。这种基于适体的扩增级联既不需要使用酶的扩增阶段，也不需要预处理步骤如洗涤，病毒分离,和基因提取。该测定法可以将SARS-CoV-2与其他呼吸道病毒区分开，并在室温下30分钟内检测到高达1.0PFU/SARS-CoV-2的测定法。在35个鼻咽临床样本中,该测定法准确评估了25个阳性和10个阴性临床拭子样本，这是用定量聚合酶链反应证实的。本文报道的策略可以帮助检测液体样品中各种疾病的新出现的病原体和生物标志物。此外,开发的仅由DNA和荧光团组成的检测系统可以广泛集成到液体活检平台中以进行疾病诊断。
