Immunosensor Based on the ZnO Nanorod Networks for the Detection of H1N1 Swine Influenza Virus

This paper presents an immunosensor fabricated on patterned zinc oxide nanorod networks (ZNNs) for detecting the H1N1 swine influenza virus (H1N1 SIV). Nanostructured ZnO with a high isoelectric point (IEP, ∼9.5) possesses good absorbability for proteins with low IEPs. Hydrothermally grown ZNNs were fabricated on a patterned Au electrode (0.02 cm²) through a lift-off process. To detect the H1N1 SIV, the sandwich enzyme-linked immunosorbent assay (ELISA) method was employed in the immunosensor. The immunosensor was evaluated in an acetate buffer solution containing 3,3′,5,5′-tetramethylbenzidine (TMB) via cyclic voltammetry at various H1N1 SIV concentrations (1 pg/mL–5 ng/mL). The measurement results of the fabricated immunosensor showed that the reduction currents of TMB at 0.25 V logarithmically increased from 259.37 to 577.98 nA as the H1N1 SIV concentration changed from 1 pg/mL to 5 ng/mL. An H1N1 SIV immunosensor, based on the patterned ZNNs, was successfully realized for detecting 1 pg/mL–5 ng/mL H1N1 SIV concentrations, with a detection limit of 1 pg/mL for H1N1 SIV.