A fluorogenic 2D glycosheet for the simultaneous identification of human- and avian-receptor specificity in influenza viruses

The switch in glycan-receptor specificity of influenza viruses may cause their interspecies transmission. However, tools that can simultaneous unveil the different receptor specificities of a single virus strain, in a homogeneous solution, have been elusive. Here we show a simple yet effective 2D glycosheet that is capable of simultaneously identifying the human-and avian-glycan-receptor specificity of influenza viruses. Two fluorophores with different emission colors are coupled with avian-or human-glycan receptors. Then, the glycan-fluorophore conjugates with different receptors and emission colors are co-assembled on a 2D molybdenum disulfide platform, producing a duplexed, fluorogenic 2D glycosheet. While the system shows a single emission color with viruses containing a single receptor specificity, in the presence of a virus (H7N9) containing dual (human- and avian-) receptor specificity the system produces both emission colors. Interestingly, the use of graphene oxide and carbon nanotubes as the material substrate also produces dual emission with H7N9, thus enabling a new generation of low-dimensional glyco-materials for effectively probing the switch in receptor-specificity of influenza viruses.