Rapid and universal detection of SARS-CoV-2 and influenza A virus using a reusable dual-channel optic fiber immunosensor

Establishment of rapid on-site detection technology capable of concurrently detecting SARS-Cov-2 and influenza A virus is urgent to effectively control the epidemic from these two types of important viruses. Accordingly, we developed a reusable dual-channel optical fiber immunosensor (DOFIS), which utilized the evanescent wave-sensing properties and tandem detection mode of the mobile phase, effectively accelerating the detection process such that it can be completed within 10 min. It could detect the nucleoprotein of multiple influenza A viruses (H1N1, H3N2, and H7N9), as well as the spike proteins of the SARS-CoV-2 Omicron and Delta variants, and could respond to 20 TCID50/ml SARS-CoV-2 pseudovirus and 100 TCID50/ml influenza A (A/PR/8/H1N1), presenting lower limit of detection and wider linear range than enzyme-linked immunosorbent assay. The detection results on 26 clinical samples for SARS-CoV-2 demonstrated its specificity (100%) and sensitivity (94%), much higher than the sensitivity of commercial colloidal gold test strip (35%). Particularly, DOFIS might be reused more than 80 times, showing not only cost-saving but also potential in real-time monitoring of the pathogenic viruses. Therefore, this newly-developed DOFIS platform is low cost, simple to operate, and has broad spectrum detection capabilities for SARS-CoV-2 mutations and multiple influenza A strains. It may prove suitable for deployment as a rapid on-site screening and surveillance technique for infectious disease.