Functional nucleic acids as modular components against SARS-CoV-2: From diagnosis to therapeutics.

Coronavirus Disease 2019 (COVID-19), which poses an extremely serious global impact on human public healthcare, represents a high transmission and disease-causing viral infection caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that is expanding at a rapid pace. Therefore, it is urgent for researchers to establish effective platforms for the assay and treatment of SARS-CoV-2. Functional nucleic acids (FNAs), comprising aptamers and nucleases, are of primary concern within the biological and medical communities owing of the distinctive properties of their target recognition and catalysis. This review will concentrate on the essential aspects of insights regarding FNAs and their technological expertise for the diagnostic and therapeutic utilization against COVID-19. We first offer a historical perspective of the COVID-19 pandemics, its clinical characteristics and potential biomarkers. Then, we briefly discuss the current diagnostic and therapeutic methodology towards COVID-19, highlighting the superiorities and existing shortcomings. After that, we introduce the key features of FNAs, and summarize recent progress of in vitro selection of FNAs for SARS-CoV-2 specific proteins and RNAs, followed by highlighting the general concept of translating FNAs into functional probes for diagnostic and therapeutic purposes. Then, we critically review the emerging FNAs-based diagnostic and therapeutic strategies that are fast, precise, efficient, and highly specific to fight COVID-19. Finally, we identify remaining challenges and offer future outlook of this emerging field.