PDF(Pubmed)
Abstract：
The development of rapid detection tools for viruses is vital for the prevention of pandemics and biothreats. Aptamers that target inactivated viruses are attractive for sensors due to their improved biosafety. Here, we evaluated a DNA aptamer (named as 6.9) that specifically binds to the inactivated SARS-CoV-2 virus with a low dissociation constant (KD = 9.6 nM) for the first time. Based on aptamer 6.9, we developed a fiber-optic evanescent wave (FOEW) biosensor. Inactivated SARS-CoV-2 and the Cy5.5-tagged short complementary strand competitively bound with the aptamer immobilized on the surface of the sensor. The detection of the inactivated SARS-CoV-2 virus was realized within six minutes with a limit of detection (LOD, S/N = 3) of 740 fg/mL. We also developed an electrochemical impedance aptasensor which exhibited an LOD of 5.1 fg/mL and high specificity. We further demonstrated that the LODs of the FOEW and electrochemical impedance aptasensors were, respectively, more than 1000 and 100,000 times lower than those of commercial colloidal gold test strips. We foresee that the facile aptamer isolation process and sensor design can be easily extended for the detection of other inactivated viruses.
摘要：
病毒快速检测工具的开发对于预防大流行和生物威胁至关重要。靶向灭活病毒的适体由于其改进的生物安全性而对传感器具有吸引力。这里,我们首次评估了与灭活的SARS-CoV-2病毒特异性结合的低解离常数（KD=9.6nM）的DNA适体（命名为6.9）。基于适体6.9，我们开发了光纤消逝波（FOEW）生物传感器。失活的SARS-CoV-2和Cy5.5标记的短互补链与固定在传感器表面上的适体竞争结合。在6分钟内实现了对灭活的SARS-CoV-2病毒的检测，并具有检测限（LOD，740fg/mL的S/N=3)。我们还开发了一种表现出5.1fg/mL的LOD和高特异性的电化学阻抗传感器。我们进一步证明了FOEW和电化学阻抗传感器的LOD，分别,比商用胶体金试纸低1000和100,000倍以上。我们预见到,容易的适体分离过程和传感器设计可以容易地扩展用于其它灭活病毒的检测。
