PDF(Pubmed)
Abstract：
Fast and effective diagnosis is the first step in monitoring the current coronavirus 2 (CoV-2) pandemic. Herein, we establish a simple and sensitive electrochemical assay using magnetic nanocomposite and DNA sandwich probes to rapidly quantify the CoV-2 nucleocapsid (N) gene down to the 0.37 fM level. This assay uses a pair of specific DNA probes. The capture probe is covalently conjugated to Au-decorated magnetic reduced graphene oxide (AMrGO) nanocomposite for efficiently capturing target RNA. In contrast, the detection probe is linked to peroxidase for signal amplification. The probes target the COV-2 gene, allowing for specific magnetic separation, enzymatic signal amplification, and subsequent generation of voltammetric current with a total assay time of 45 min. The developed biosensor has high selectivity and can discriminate non-specific gene sequences. Synthetic COV-2 N-gene can be detected efficiently in serum and saliva, while 1-bp mismatch gene yielded a low response. The performance of the genosensor was good in an extensive linear range of 5 aM-50 pM. For synthetic N-gene, we achieved the detection limit of 0.37, 0.33, and 0.19 fM in human saliva, urine, and serum. This simple, selective, and sensitive genosensor could have various genetics-based biosensing and diagnostic applications.
摘要：
快速有效的诊断是监测当前冠状病毒2（CoV-2）大流行的第一步。在这里，我们使用磁性纳米复合材料和DNA夹心探针建立了简单而灵敏的电化学测定法，以快速定量CoV-2核衣壳（N）基因至0.37fM水平。该测定使用一对特异性DNA探针。捕获探针与Au修饰的磁性还原氧化石墨烯(AMrGO)纳米复合材料共价缀合,以有效捕获靶RNA。相比之下,检测探针与过氧化物酶连接用于信号放大。探针靶向COV-2基因,允许特定的磁分离，酶信号放大，和随后产生的伏安电流与45分钟的总测定时间。所开发的生物传感器具有较高的选择性，可以区分非特异性基因序列。合成的COV-2N基因可以在血清和唾液中高效检测,而1-bp错配基因产生的反应较低。基因传感器的性能在5aM-50pM的广泛线性范围内良好。对于合成的N基因，我们在人类唾液中达到了0.37、0.33和0.19fM的检测限，尿液,和血清。这个简单的，选择性,和敏感的基因传感器可以有各种基于遗传学的生物传感和诊断应用。
