) Schematic route to prepare an N-terminal LA-EG11-linker labelled lectin (A) and further to make a polyvalent nano-lectin (B) exemplified using DC-SIGN CRD as a model lectin. Lectin N-terminal α-amine is selectively labelled with a LA-EG11-linker by reacting with LA-EG11-TFP at pH 6.2. Citrate stabilised 13 nm gold nanoparticle (G13) is first partially PEGylated with HS-EG7-OH to form ppG13-OH to improve its stability in buffer, and then conjugated with LA-EG11-linker labeled CRDs conveniently via self-assembly to form G13-CRD. (C) Schematic show of possible bindings of G13-CRD on viral surface S-protein glycans: (C1) binding on top that sterically blocks viral receptor binding domain access to host ACE2; and (C2) binding with two S-proteins simultaneously on virion surface, leading to crosslinking of S-proteins and hence interruption of S-protein conformational changes to inhibit viral infection.