Detection of Avian Influenza Type A H3N2 Virus Antigens in Microchannel and Droplet Microfluidics

摘要

Virus antigens of avian influenza type A H3N2 were detected on two different microfluidic platforms (microchannel and droplet). Latex immunoagglutination assays were performed using 390 and 920 nm highly carboxylated polystyrene beads that were conjugated with antibody to avian influenza type A virus. The bead suspension was merged with the solutions of avian influenza virus antigens in the Y-junction of a microchannel, made by polydimethyl siloxane soft lithography, through which 45° forward light scattering was measured. Alternatively, 10 µ L droplets of a bead suspension and an antigen solution were merged on a superhydrophobic surface (water contact angle = 155°), their movement was guided by a metal wire, and 180° back light scattering was measured. All optical measurements were made on micropositioning stages to help generate reproducible optical signals. Microfluidic manipulations and optical detections were made simultaneously in a single setup. Detection limits were 1.0 to 2.2 fg per assay, or 0.1 pg mL -1 , which is superior to any reported methods of detecting avian influenza type A virus by several orders of magnitude. Total assay time was less than 10 min