Enhanced target recognition of nanoparticles by cocktail PEGylation with chains of varying lengths.

Monodispersed gold nanoparticles (AuNPs) were simultaneously decorated with lactosylated and non-modified shorter poly(ethylene glycol)s (PEGs) to enhance their target recognition. The decoration with sufficiently shorter PEGs dramatically enhanced the multivalent binding ability of lactosylated AuNPs to the lectin-fixed surface, possibly due to the enhanced mobility of the ligands via the spacer effect generated by the shorter PEG chains.