Functional nucleic acid-based biosensors for virus detection

A growing number of viruses pose significant threats to human health, impact agricultural production and compromise food safety. Minimizing the impact of viral infections demands for effective technologies that can deliver sensitive viral detection under various settings. Functional nucleic acids (FNAs) – natural or synthetic nucleic acid molecules with catalytic and/or binding properties – have been increasingly explored as key components for setting up diagnostic tests for viral detection. FNA-based viral biosensors offer distinct advantages, such as the ability to achieve sensitive viral detection in complex biological samples, ease of use, scalability, and cost-effectiveness. This mini-review will be dedicated to appraising progress made in recent years in FNA-based biosensors for diagnosing diverse human and animal viruses. We will first describe virus structures and potential biomarkers that can be utilized as the targets for FNA probe engineering. This is followed by reviewing the latest advances in two classes of FNAs - DNAzyme and DNA aptamers, with focuses on DNAzyme- and DNA aptamer-based biosensors that employ diverse signal transduction mechanisms to achieve sensitive viral detections. Finally, we will discuss current challenges in the field and suggest future research directions that can address these challenges.