Dual immunosensor based on methylene blue-electroadsorbed graphene oxide for rapid detection of the influenza A virus antigen

•Fabrication of methylene blue-electroadsorbed graphene oxide as sensor platform.•Chitosan and protein-A layers enrich the bioactivity of immobilized antibodies.•Monoclonal antibody-modified electrodes selectively sense the H5N1/H1N1 antigens.•Dual immunosensor based on dye-graphene oxide allows rapid flu-diagnostics.

Rapid detection of influenza viral infections in poultry facilities is advantageous in several aspects such as environmental/personal safety, food-security, and socio-economy. Herein, we report the development of an electrochemical-based dual-sensor platform composed of methylene blue-electroadsorbed graphene oxide nanostructures modified with monoclonal antibodies against the HA proteins of H5N1 and H1N1. Bio-functional layers comprised of chitosan and protein-A molecules were implemented at the interface of the sensor element and antibodies, which synergistically enriched the bio-activity of immobilized antibodies for the immune complex formation. The differential pulse voltammetric signals resulted from the developed immunosensor platform exhibited a good correlation (R2=0.9978 for H1N1 and R2=0.9997 for H5N1) for the wide range of target concentrations 25–500 pM). Chronoamperometric study also revealed the amplified current sensitivity of the immunoelectrodes even at the picomolar level. The proposed immunosensor design not only provides rapid analytical response time (<1 min) but simplicity in fabrication and instrumentation, which paves an attractive platform for on-farm monitoring of viral infections.

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