Combined gold nanoparticle-antibody conjugate enhances sensitivity of influenza a antigen detection in lateral flow assay

A combined gold nanoparticle (GNP)-monoclonal antibody (MAb) conjugate was generated for a direct influenza A antigen detection using lateral flow assay (LF) format. The combination of GNP-MAb conjugate targeting both nucleoprotein (NP) and matrix protein (M) allows the detection of multiple influenza A proteins. The LF system consisting of combined GNP-MAb conjugate showed an improved sensitivity, compared to the LF system containing single GNP-MAb conjugate targeting only one target protein, either NP or M. This was illustrated by the 2- to 260-fold lower limit of detection of the combined GNP-MAb conjugate LF than the single GNP-MAb conjugate LF. As such, the combined GNP-MAb conjugate LF could provide the basis for developing a direct influenza A antigen detection for rapid influenza A diagnosis.