Multivalent Sialyllactose-Levan-Conjugated Gold Nanoparticles for Efficient Interaction with and Colorimetric Detection of Influenza A Virus

We report a colorimetric assay to detect influenza A virus using sialyllactose-levan-conjugated gold nanoparticles (AuNPs). We successfully conjugated 2, 3- and 2, 6-sialyllactose to levan and synthesized sialyllactose-levan-conjugated AuNPs. Each sialyllactose-conjugated levan specifically interacted with a recognizable lectin. Synthesized sialyllactose-conjugated levan acted as reducing and coating agents during the formation of AuNPs. Human influenza A virus specifically bound to 2, 6-sialyllactose-levan-conjugated AuNPs. Moreover, 2, 6-sialyllactose-conjugated levan AuNPs rapidly changed color from red to blue after incubation with human influenza virus. For detecting avian influenza virus, 2, 3-sialyllactose-levan-conjugated AuNPs were more effective than 2, 6-sialyllactose-levan-conjugated AuNPs. Therefore, the efficient targeting and diagnosis of influenza virus according to origin was possible. The deployment of sialyllactose-levan-conjugated particles for the detection of influenza virus is simple and quick. The limit of detection (L.O.D) of H1N1 influenza virus was 7.4 x 10(3) pfu using 2, 6-siallylactose-levan-conjugated AuNPs and H5N2 influenza virus was 4.2 x 10(3) pfu using 2, 3-siallylactose-levan- conjugated AuNPs.

Automated summary

A colorimetric assay using sialyllactose-levan-conjugated gold nanoparticles was developed for detecting influenza A virus, with efficient targeting and diagnosis based on the virus's origin. The method allowed for quick and simple detection, with different sialyllactose conjugates showing varying effectiveness for different strains of influenza virus.