LA-EG4-psDiMan: Preparation of Gx-psDiMan conjugates. 5 nm GNPs (G5s) were synthesized in house using citrate reduction of HAuCl4 in the presence of a small amount of tannic acid by following a literature method. 13 nm GNPs (G13s) were synthesized by the standard citrate reduction method as reported previously. For G5-psDiMan conjugation, citrate stabilized G5 was pre-concentrated via centrifugation by 4000 rpm, 20 min using a 10 kDa MWCO filter. The concentrated G5 aqueous solution was then added to a ligand mixture of LA-EG4-psDiMan and LA-EG2-EG2-OH (with LA-EG4-psDiMan content varying from 100, 75, 50, 25, 12.5, 6.3 and 0%) under a fixed total ligand: G5 molar ratio of 1000:1 and incubated at room temperature for 48 h with shaking to make G5-psDiMan via self-assembly. Any unbound ligands were then removed by washing the G5-psDiMan conjugates with deionized water using a 10 kDa cut-off MWCO filter via centrifugation by 10,000 ×g, 5 min for 3 times. The washing and flow through liquids were collected and combined to determine the amount of unbound LA-EG4-psDiMan ligand to calculate GNP surface glycan valency. For G13-psDiMan conjugation, citrate stabilized G13 was added to the mixed LA-EG4-psDiMan and LA-EG2-EG2-OH ligands (varying ratios as above) under a fixed total ligand: G13 molar ratio of 3000: 1 in a glass vial. The mixture was sonicated for 2 min, then incubated for a further 48 h at room temperature to complete G13-psDiMan conjugation. After that, the G13-psDiMan conjugates were transferred to Eppendorf tubes pretreated by 0.2% Tween 20, centrifuged at 17000 g, 30 min and washed with deionized water 3 times. The supernatant and washing liquids were collected to measure the amount of unbound LA-EG4-psDiMan ligands to calculate their glycan valency. The Gx-psDiMan conjugates were dispersed in pure water and their concentrations were calculated from their SPR peak absorbance at ~515 and ~520 nm using a molar extinction coefficient of 6.3 x 10 6 M -1 cm -1 and 2.32 x 10 8 M -1 cm -1 for G5 and G13, respectively.