Considering the worldwide health crisis associated with highly contagious severe respiratory disease of COVID-19 outbreak, the development of multiplexed, simple and rapid diagnostic platforms to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is in high demand. Here, a nucleic acid amplification-free electrochemical biosensor based on four-way junction (4-WJ) hybridization is presented for the detection of SARS-CoV-2. To form a 4-WJ structure, a Universal DNA-Hairpin (UDH) probe is hybridized with two adaptor strands and a SARS-CoV-2 RNA target. One of the adaptor strands is functionalized with a redox mediator that can be detected using an electrochemical biosensor. The biosensor could simultaneously detect 5.0 and 6.8 ag/μL of S and Orf1ab genes, respectively, within 1 h. The biosensor was evaluated with 21 clinical samples (16 positive and 5 negative). The results revealed a satisfactory agreement with qRT-PCR. In conclusion, this biosensor has the potential to be used as an on-site, real-time diagnostic test for COVID-19.

考虑到与 COVID-19 爆发的高度传染性严重呼吸道疾病相关的全球健康危机，迫切需要开发用于检测严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) 的多重、简单和快速诊断平台。在这里，提出了一种基于四向连接 (4-WJ) 杂交的无核酸扩增电化学生物传感器，用于检测 SARS-CoV-2。为了形成 4-WJ 结构，通用 DNA 发夹 (UDH) 探针与两条接头链和一个 SARS-CoV-2 RNA 靶标杂交。其中一个接头链被氧化还原介体功能化，可以使用电化学生物传感器检测。该生物传感器可在 1 小时内分别同时检测到 5.0 和 6.8 ag/μL 的 S 和 Orf1ab 基因。生物传感器用 21 个临床样本（16 个阳性和 5 个阴性）进行了评估。结果显示与 qRT-PCR 令人满意。总之，这种生物传感器有可能用作 COVID-19 的现场实时诊断测试。