RAPID: Enzyme-free detection of coronavirus RNA using reconfigurable DNA nanoswitches

控制当前COVID-19疫情的一个关键方面是早期和快速检测受感染人群。 目前检测导致COVID-19的新型冠状病毒的方法通常需要实验室，并使用昂贵的设备和试剂。 这些要求限制了全国范围内可以进行的测试数量。 在这个项目中，研究小组的目标是开发一种替代的诊断方法，直接检测病毒RNA，而不需要任何扩增、标记或使用酶。 该分析需要最少的步骤，并使用一个紧凑的，无缓冲的凝胶盒系统，可以在临床环境中部署。 除了目前的COVID-19疫情，这种传感平台还可以应用于其他现有或新兴的病毒。这项工作旨在开发一种灵敏度足以在1小时内检测临床水平的SARS-CoV-2病毒RNA的纳米开关检测方法。 一旦从样品中提取出病毒RNA，RNA就会被片段化并与基于DNA的纳米开关混合。 特定序列的病毒RNA片段与纳米开关的杂交诱导工程化DNA链从其线性“关闭”状态到环状“打开”状态的构象变化。 通过凝胶盒系统中的电泳将目标结合的环状形式与线性纳米开关分离后，通过凝胶图像中环状（上）纳米开关的强度来量化病毒载量。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

A critical aspect of controlling the current COVID-19 outbreaks is early and fast detection of the infected population. Current methods for detecting the novel coronavirus that causes COVID-19 typically require a laboratory and use expensive equipment and reagents. These requirements limit the number of tests that can be performed nationwide. In this project, the research team aims to develop an alternative diagnostic approach that directly detects the viral RNA without any amplification, labeling, or the use of enzymes. The assay requires minimal steps and uses a compact, bufferless gel cartridge system that can be deployed in a clinical setting. Beyond the current COVID-19 outbreak, this sensing platform can also apply to other existing or emerging viruses.This work aims to develop a nanoswitch assay sensitive enough to detect clinical levels of SARS-CoV-2 viral RNA within 1 hour. Once the viral RNA is extracted from a sample, the RNA is fragmented and mixed with the DNA-based nanoswitches. Hybridization of a viral RNA fragment of a specific sequence with a nanoswitch induces a conformational change of the engineered DNA strand from its linear "off" state to a looped "on" state. After separation of the target-bound looped form from the linear nanoswitches by electrophoresis in a gel cartridge system, the viral load is quantified from the intensity of the looped (on) nanoswitches in a gel image.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.