Rapid influenza a antigen detection using carbon nanostrings as label for lateral flow immunochromatographic assay

In this study, we investigated a feasibility of using carbon nanostrings as reporters in developing a lateral flow immunochromatographic system for a rapid influenza A antigen detection as a model. Carbon nanostrings were successfully conjugated to monoclonal antibody specific to the nucleoprotein, one of the most abundant influenza A protein, for a signal visualization. To demonstrate the feasibility of the lateral flow immunochromatographic system using carbon nanostrings as reporters for influenza A antigen detection, the system was applied to detect the antigen in an allantoic fluid infected with pandemic 2009 influenza A H1N1 virus. It was shown that the system was able to detect the influenza A nucleoprotein in a complex biological fluid such as an infected allantoic fluid containing 2.8×103 TCID50/mL (50% tissue culture infectious dose). By using carbon nanostrings as reporters combined with lateral flow immunoassay as the mean of antigen detection, a specific recognition of influenza A antigen could be achieved within 15 min. Compared to the existing methods of influenza A diagnosis such as viral isolation and serological approaches, this simple one-step immunochromatographic system avoids laborious and multiple incubation steps, as well as maintaining a sensitive and specific detection which could be useful for developing a point-of-care diagnostic test in other applications.