Zinc oxide nanorod integrated microdevice for multiplex virus detection

Technology development for point-of-care viral pathogen detection is critical for early diagnosis of infectious diseases, and rapid and effective disease intervention. In this paper, we present the development of a zinc oxide nanorod-integrated microdevice for highly sensitive and specific detection of avian influenza virus. This multiplexed immunofluorescence platform takes two advantages of the zinc oxide nanorods. On one hand, the 3D morphology of zinc oxide nanorods efficiently increases the effective surface area for monoclonal antibodies and decreases the diffusion distance between antibody and pathogens. On the other hand, the unique optical property of the translucent randomly ordered zinc oxide nanorod surface enhances fluorescence detection by 30-70%. We demonstrated the detection limit of the H5N2 avian influenza virus could be lowered down to 3.6×10³ EID₅₀/mL (EID50: 50% embryo infectious dose), which was about 22 times more sensitive than conventional ELISA assay tested under the same conditions. We further designed the microfluidic biosensor platform to detect multiple viruses simultaneously by spatial encoding of capture antibodies. One prominent feature of the device is that the captured H5N2 avian influenza virus can be released by simply dissolving zinc oxide nanorods under slightly acidic environment for subsequent off-chip analyses. As a whole, this platform provides a powerful tool for rapid detection of multiple pathogens, which may extent to the other fields for low-cost and convenient biomarker detection.