Facile, Rapid, and Low-Cost Detection for Influenza Viruses and Respiratory Syncytial Virus Based on a Catalytic DNA Assembly Circuit

[Image: see text] Influenza viruses and respiratory syncytial virus (RSV) have contributed to severe respiratory infections, causing huge economic and healthcare burdens. To achieve rapid and precise detection of influenza viruses and RSV, we proposed a catalytic hairpin assembly (CHA) combined with the lateral flow immunoassay (CHA–LFIA) detection method. The presence of the target RNA triggers the initiation of CHA circuits. H1/H2 complexes, the amplified signal products, which were labeled with digoxin and biotin, were detected with a highly sensitive lateral flow immunoassay system. The sensitivity of the CHA–LFIA system to influenza A and B viruses and RSV reached up to 1, 1, and 5 pM, respectively. In addition, this method exhibited excellent capability for differentiating between target RNA and base-mismatched RNA. The results demonstrated that an enzyme-free, rapid, highly sensitive, and specific method had been developed to detect influenza A and B viruses and RSV.